My GPW looks funny under the sun in the front section. My hood is still very white, the fenders look a bit yellow-ish in its white, and the front bumper is the front-bumper is some where in the middle. I guess that's because the S has aluminum, steel, and plastic in those 3 places

Does anyone else have that problem? Mine's an 04 ...

 

No but I believe you've answered your own question. Except I believe that the the front bumper is eurathane(flexible & bendable to a certain extent). Don't forget about the curvature, is that even a word? Anyways, of the body panels. That will also reflect the light differently.