Have you even played Saint's Row?Most of the GTA games you couldn't mod your car it didn't suck 100% because GTA:SA the only gta game i played which you can really mod your car, doesn't have very many options. In Saint's Row you can change rim color and alot more then any gta game unless GTAIV will have that feature and it's alot better(this isn't just based on modding cars there respect and graphics too)
I played it numerous times!! It sucks ass. All gta games can be modded!! As far as the damn rims are concerned even they can be modded!!