Just curious why this happens to paint. This is not my car, but I have one just like it, and I'm starting to see something like that on the hood, and I've seen it on other cars. It's much less noticeable on my vehicle but still really annoys me because it's original paint, it's in mint condition except for that spot that's starting to develop.

Separation of the base and top coats caused by different expansion rates. It's agravated by the sun, exhaust manifold and possibly lack of underhood pad.

I was told that it is the clear coat breaking down. I never quite understood it though as I have been under the impression that the original paint was a single stage job - not base coat, clear coat...

So, whatever I have just told you, please do not take it as the absolute truth!

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Dale

Is there any way to prevent further damage?

Stay out of the sun, make sure hood pad is in place, open hood when parked-keeps it cooler. There really isn't much in the practical sense you can do.

Thanks, Chas H. Padding is excellent and the spot that's developing isn't even over the manifold. It's that damn shiny sun!

answer is, to achieve any type of gold, tan or red tint in paint the way they do it adding iron oxide... basically rust particles, doesn't rust the car out but the finish will oxidize quicker than blue or white or green or even silver....red goes first....gold/tan second...simple composition

^ Agreed. I brought my paint back to life using the cleaner wax, claybar, (added step of Ultimate Compound) then Gold Class Liquid Wax.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

My 1988 300SEL is just starting to do this on top between sunroof and the windshield.

Happened to my 300E too, but it spent 20 years in Las Vegas....so it is well baked. Eventually I will repaint it....

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

If this occurred on a newer car than I would say that the clear coat or the application was faulty. Environmental causes are said to be acid rain related, sun so forth... The only true way to make this repair is to have a shop strip down the clear and base coat and respray to match. I personally prefer a single stage polyurethane enamel with many coats and with a gloss "wet look" additive. This way if the paint gets dull, you can always wet sand it and buffer the original color back. With Clear coat systems like you have, once you've gone through the Clear coat, your done. Those paint restoratives will not do much when the clear is gone, it will only continue and get worse. Steve

There's nothing you can do once the clear coat starts peeling like in that photo. The only fix is to repaint.

Some Mercedes colors were single stage, and some base/clear. Metallic colors are tri-coats and the "blah" colors were single stage. I personally prefer the single stage paint...it can be neglected for 20 years, and be buffed back to looking new in an afternoon.

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles