i never encountered this problem until a year ago.

i acquired a 2006 cl500 from a benz dealer. all switches. all plastics were firm.

then, that benz went to another benz dealer. and suddenly, all the steering wheel switches were sticky. and dissolving.

i attributed that to some chemical compound being used by the "make ready" contractor crew[new feature at m-b sugarland - no longer their employees].

m-b sugarland denied that their contractor crew used anything other than water and clean rags to dust a car interior. but, they did replace all the steering wheel switches.

that vehicle has never been back to them. until last week. steering wheel switches are still firm, but the headlight switch eschutcheon is dissolving in a strange fashion. not uniformly, but as if someone used a chemical compound on a rag with their fingers[you can see the fingerprints melted into the plastic]. and then, i think someone must have said to the outside contractor, don't use that. because the dissolving is confined to spots on the left side of that escutcheon.

has anyone else experienced this issue?

the m-b dealer has tried to tell me that it is the plastic deteriorating from uv and high temperatures.

funny, this car spends most of its time in an airconditioned garage with no windows.

and i have never seen this dissolving with any of the other plastics in my other benzes.

problem seems to have started when this dealership decided to use outside contractors for its make-ready crew.

any thoughts from the bleacher seats?

I have a similar "dissolution" on the inside of the storage cubby above the ashtray. I don't know for sure, but I think it is the "Softlack" paint from Mankiewicz that can't stand up to Florida heat. I also have an '05 Jetta that is looking disgusting because of what seems to be the same thing. I'm not sure if there's a spray can repair soluton.

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Prost!

Honestly MB sugarland are a strange bunch. Their parts sales hates me while their service dept thinks Im poor and from the moon because I drive ancient (according to their sales) MB sedans - one dressed up lady told me that my diesel benz is dead because its engine is rattling

anyway - I have seen this button and plastics deterioration and its caused by using overly caustic solutions and some solutions with petroleum distillates in them. Its not just an MB thing. And if it were heat etc. the plastics wont melt but literally crumble (try an old chevy truck)

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

The steering wheel buttons got all gooey on my grandfathers 03 CLK430 with 35k miles on it. No idea what caused it, however it lived in Florida with the top down, so I could see the UV thing but that car was always garaged at night or whenever at home.

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68 280SL - 70 280SL - 70 300SEL 3.5 - 72 350SL - 72 280SEL 4.5 - 72 220 - 72 220D - 73 450SL - 84 230GE - 87 200TD - 90 190E 2.0 - 03 G500

Nissan GTR - Nissan Skyline GTS25T - Toyota GTFour - Rover Mini - Toyota Land Cruiser HJ60 - Cadillac Eldorado - BMW E30 - BMW 135i

Plastic outgasses as it ages making things sticky.

When I had my shop, some customers cars would sit unused for a few months as they decided if an engine replacement was worth it, engine found and shop time scheduled. With the car being unused, steering wheels and other plastics would sometimes get sticky. This outgassing is constantly occurring but as the car is used the stickiness wears off.

I just moved a mid 90's Ford that I had stored in a shaded semi trailer for 3 + years. The steering wheel felt like contact cement and looked wet with oil but it was dry when I put in storage.

How long was the car at the dealer? The only chemical I'd think that would attack plastic like you are describing is brake cleaner.

over the memorial day weekend.

and i had my cl55 there the next week for a four set wheel replacement for the same period of time[3-4 days].

both these cars have the same mileage[approx 50k]. they both live in either in an air-conditioned warehouse, no windows. or in my non-airconditioned garage, no windows.

and i have a few other benzes, you know. a 1987 560sec, a 1995 e320 cab, a 1997 s500c, a 1979 6.9, and until february a 1986 560sel[256,000 miles - donated it to local public radio].

none exhibit any sticky switches.

since m-b sugarland hired "make ready" contractors, only the 2006 cl500 may have gone through that process. and it was weird, i purchased this car as a cpo from m-b greenway. no "sticky" switches.

then, the m-b regional tech rep had it pulled from that dealership for cpo prep because m-b greenway seemed unable to perform that cpo level of prep. he sent it sugarland[not an autonation store]. then, when i went to pick it up from them, virtually all the steering wheel switches were sticky, and in the state of dissolving[black plastic came off on my index finger].

i think that the cl55 avoided that since it was only having its wheels replaced.

i remain convinced that someone in that "make ready" operation is applying nasty chemicals to the plastics.

Over a weekend isn't enough time to see the outgassing effect I speak of so it does appear that there was a bad reaction. However I'd think the plastic was aging and what ever was applied helped things along rather than a one time attack.

I tend to stay away from detailing shops as they use harsh chemicals that , while they clean things up, take life out of a vehicle. ( I've been in / around the auto repair business for many years.)

of course, it wasn't a detailing shop.

it was the sugarland mercedes-benz dealer.

and no detailing was specified by this customer. like you, i don't believe in it.

no, this dealer decided to out-source its make ready personnel. and i don't think that those personnel really know what they are doing.

and i shall leave it at that.

The Benz Vehicles with all the fancy controls on the steering wheel have a rubberized coating on the buttons-Anti slip coating. This Anti Slip coating from one week to the next will go from normal rubberized coating to a gooey mess in no time flat!!

Those steering wheel switches are in the three-figures for each set!! Not including removal and installation. It may set you back in the low four figures!! It pays to diy here...

What I did? Disconnected the battery.Removed the airbag. Removed the steering wheel. Removed the switches. Used this plastic cleaner from Eienszett

Plastic Deep Cleaner | einszett Car Care Products.

It was strong enough to soften the rubber coating, but not strong enough to melt through to the plastic like a solvent would. I cleaned it the rubber coating with a tooth brush and paper towel, Yet I wanted to try the Goo Gone(yellow liquid-which is designed to remove sticky decal residue), but I did not have any at hand, but Goo Gone is available at the 99cent stores.. Now my buttons have a shine like dash that has Amour All on it. That is way better than the bubble gum coating I had before...

Best of luck,

Martin

Mava, this brings a new wrinkle to the issue. When the OP was describing plastic, I was thinking hard plastic not rubber coated. I now wonder if the rubber coating had been failing all along and developed a non sticky skin. When the car was cleaned, this skin was washed off leaving the previously hidden sticky mess.

So, if this is the case, the cleaning shop isn't liable as they had no way of knowing that cleaning would cause a problem. If the owner had cleaned the plastic with Windex they might have had the same problem. The only way to be sure is to post on more message boards asking if others have similar problems.

excuse me, but i consider this a red herring.

my 2006 215 series cars have hard plastic switches.

not rubber.

nor rubberized.

and, as i said, the only time i found them dissolving was when m-b dealer turned over its make ready crew to an independent contractor.

My 2002 E320 has the thin rubber coated hard plastic switches. In my case, after my switches got gooey-not when the switches felt like hard rubber tire. Any cleaning chemical would upset the gooey to more gooey...

Martin

perhaps you are accurate.

but here is what i have encountered.

A. when i acquired a 2006 cl500[pewter silver, charcoal interior] in march 2009. all switches, all plastic were hard and smooth. this was one-owner[lessee] and was sold as a cpo'ed car by m-b houston north[an autonation store].

though this dealership avoided living up to all the cpo conditions established by mbusa, that i knew the local tech rep did coerce them to finally live up to the cpo terms.

something important is that this car was leased by a gastroenterologist in december 2005. it was never garaged at his residence in the woodlands. it was only driven from his residence to his office. where it was exposed to houston heat and sunshine.

after i acquired it, it became my mostly daily driver. that meant that it spent nights in my un-airconditioned garage. and days exposed to the heat and sunlight in my corporate parking lot.

when i purchased it, it had 19,200 miles as i recall. when i sold it in january 2013, it had approx 46,000 miles.

when i purchased it, when i sold it: NO STICKY SWITCHES - NO DISSOLVING PLASTIC.

B. in december 2010, looking for a used, cpo'ed CL55, i found one at m-b sfo.

it was a one owner[lessee] car that spent all of its original operator's life in monterey/hollister, ca. it had approx 43,000 miles. it was brilliant silver with a java interior. though i did not inspect it in sfo before it was shipped to me, it arrived in virtually new condition. no dings. its only flaws were some "curbed" chrome-plated, two piece wheels.

all switches. all dashboard plastics were hard, not sticky.

this car has never been a daily driver, but it does get driven. when not driven it lives in a windowless, air-conditioned warehouse. when driven, it resides in an un-airconditioned garage at night. and in the daytime, will sit in a parking lot exposed to houston heat and uv.

over the last 2+ years, it has also spent some time at sugarland m-b dealership.

as of today, at almost 51,000 miles, there are no STICKY switches. NO EVIDENCE OF DISSOLVING PLASTICS.

C. having owned benzes since 1973, mbna was a notorious for loading its cars. as i recall, the only option for years was orthopedic seats.

so, it suprised me after i acquired my first 215 coupe in 2009 that the keyless go was one option of many.

and options that i would have wanted. and options that i would have wanted.

recognizing that mbusa had decided to play an options game, the 2006 cl55 that i acquired had all of them.

and i looked for a 2006 cl500 with all of them. found one. regrettably at another autonation store[m-b greenway]. brilliant silver. charcoal interior.

it was cpo'ed. inspecting it, i noted some deficiencies.

but, at that pre-purchase inspection, all switches[especially steering wheel switches were all black with white icons. nothing in the interior was sticky.

i gave this dealership a punch list of aspects of the car that needed to be corrected[should have been corrected before it was offered for sale as a cpo'ed car].

when i was informed that those deficiencies had been corrected, i went to that dealership to pick it up. much to my astonishment, none had been corrected. and there were new deficiencies.

the most interesting one was how some of the steering wheel switches had been so "buffed" that the black surface with icons had been eradicated. some of the switches were now down to the white nylon base layer.

but none of those steering wheel switches that were still black with icons were sticky.

eventually, m-b greenway admitted that they had made no efforts to correct the deficiencies that were on my punch list. nor would they. once again, my local mbusa tech rep intervened and this cl500 was transported to m-b sugarland to put in into proper cpo condition.

and m-b sugarland mostly squared it away. as i recall, the two switches that had been buffed down to the white nylon substrate had been replaced. but, now, all the steering wheel switches were sticky. even the new ones.

this is when i learned that a "make ready" contractor had replaced this dealership's in-house personnel.

i was convinced that these contractor personnel had applied some chemicals that dissolved the "finish" of these steering wheel switches, rendering them sticky.

the steering wheel switches were replaced by mbusa as a consequence of the cpo procedures.

though i am an engineer, i did not request the failed switches for my analysis.

but here is what i think i saw. the base switches are molded with a white plastic[nylon?]. then the switches are "painted" with a mask, which allows the white nylon to be revealed for the icons.

in other words, the black, java finishes for the switches are paint.

recently, this 2006 cl500 was in the m-b sugarland dealership for a warranty replacement of a crank position sensor.

picking it up on a saturday afternoon, i noticed nothing unusual about the intererior.

it was returned to its dark and air conditioned garage.

but taking it out at night some days ago, i felt that the black headlight switch escutcheon had become sticky. all of that escutcheon left of the headlight switch had become sticky. and had experienced something that melted the "paint". the right side of that escutcheon remained firm, unsticky.

it is my guess that at its heart, this bit of plastic is also a white plastic. painted black using a mask so that the white plastic is revealed for the light switch positions.

and that some make ready personnel applied some chemical to that left half that began to dissolve the paint.

i think that there is no rubberizing of these switches. they are painted and some chemicals applied initiate the dissolving of the paint.

study on that analysis.

all ears for any comments.