> even if you have a powerful car, you'll still be mocked if you put any sort of vinyls on your car
In real life or in a game? In a game, it doesn't matter to me. In real life, as posted above, some people were getting carried away with vinyls, and also stereo systems. That's not much of a fad anymore. As for Underground 2, using wide bodykits made it more likely to hit walls and also to slow the car down more if you did hit or slid along a wall, so that was a case where a visual customization, wide bodykits, adversely affected times, since at some tracks, wall riding was faster. I used vinyls in Underground and Underground 2, but would never use them on a real car. In NFS World, I left most or all of the decals that came with special versions of cars, although I did tend to change the color schemes.
For Underground, one of the vinyls had a glow effect:
http://rcgldr.net/nfs7/n7rx7.jpg
Then there was this photo shopped "6 star" car for Underground:
http://rcgldr.net/nfs7/rx7.jpg
and this unusually modified 240SX for prostreet:
http://rcgldr.net/nfsp/240sx.jpg