I had a similar problem with some ES rims on my old car, they were the 10-spoke ES rims that come with the ESs with the panoramic roof, anyway they have the same color as the G-spider wheels. You could see it up close but I didnt mind much because you really couldnt notice from further away.

 

So was I, but it is a piece of very thin plastic with very thin plastic tabs. I can't imagine damaging (scratching) the wheels as long as you don't "throw it" on the wheel. Better than overspray and cleaning wheels 2 times each time.

 

Sorry, referring to the wheel sprays, not the cover. Cover looks like a good idea.