mdotk

Even with a stage 3 cut and polish, these blotches on the hood of my black 2014 63 are not coming out... What's worse is that the bonnet is only 3 years old and someone reversed into me 3 years ago!

Has anyone encountered this before? Perhaps something to do with extreme engine temps (not that I have ever had any temperature issues). It's like the defects are in the paint itself and not the clear coat.

lo-fi

It really does look like hard water spots but man the car must have really baked in the sun drenched with water loaded with minerals if so. Tried white vinegar and water in equal parts? Maybe try a tiny test area to start with, but that is about as bad as I've ever seen.

todthedod

+1 on water spots. My mom has a black Ford Edge that has the worst etched in water spots I've ever encountered. Get a pro to try a test area with a high speed polisher (not D/A) and see if they come out. I wonder if its' possible that someone did a repair and cleared over water spots. You never know. Only widespread paint defects I've ever heard on Mercedes was the Mars red back in the day.

Diabolis

Not that it helps, but for the record I'd tend to point the finger at the fact that your bonnet (hood) is 3 years old and thus has likely been (re)painted by a third party (as opposed to the original factory Mercedes paint job). That appears to have etched itself into the paint likely while it was still fresh following the repaint. Car paint takes a month or more to properly cure depending on conditions.

If you had the hood replaced through an authorized MB dealer / body shop, the paint job should come with a lifetime warranty against defects in materials or workmanship (which is what this is) for as long as you own the car. Take it back to them.