I had the same problem on my 190D. I filled the bad spots with bondo, sanded it nicely, and went over the whole bumper with Duplicolor black bumper paint. The result is better than you'd think. It's lasted 2 years so far, and it would only take a couple of hours to redo if there was a problem.

Pics?

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Not very good photos, but you can see how it looked when it was fresh:

http://www.coolcatcorp.com/190Restoration/Mercedes50.JPG

http://www.coolcatcorp.com/190Restoration/Mercedes51.JPG

"Before", I had a six inch tear in the rear bumper.

I'll try to get a better photo later today, if it's not raining.

That looks really good! Was it in a spray can form or did you have to use your own sprayer? Did you also use it on the other black body trim parts?

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You can't always get what you want, but if you try sometime you just might find you get what you need.

I used it on most of the black, including the door handles. There are a few pieces I didn't get to, you know how that goes.

I used rattle cans with a pistol grip attachment I found in the paint store. The grip works on any spray can, just clips to the rim. Worked very well, almost like a real spray gun. Duplicolor makes this particular paint in several colors: various shades of black and grey, and some lighter shades, too.

One problem I have at the moment is with the windshield wiper...I did the transmission with this paint. I was cleaning up the engine compartment with some spray degreaser, and some overspray hit the wiper. Wrecked the paint. Easy enough to fix, it's been the only problem. It's not as solvent resistant as regular acrylic bumper paint.

That looks... surprisingly good!

If you feel like doing crack repair and sanding, I might recommend having a look at Paintscratch's color match spray paint options. I have had simply exceptional luck with their paint. It's not cheap, but I've gotten paint from them three times, and it has been a perfect match each time. In fact, the passenger fender on my E300 is Paintscratch spray, and it matches flawlessly in terms of color, depth, and gloss: