Are GPW bumpers in particular prone to yellowing over time? I ask because my front bumper looks cream-like after x amount of time between polishes. Yesterday it was polished with a DA and looks more white like the rest of the car but I worry it will yellow again. It hasn't been painted before so it's original paint. I know there are variances in bumper and body material but still, sometimes that cream look is obvious...

Is this a thing? I know the previous owner (like an absolute idiot) let the car park in the sun for long periods of time and that's why her roof deteriorated so badly until I changed it.

 

Can you see any difference in colour between the bumper and hood? This is just after it was polished yesterday.