I have never had even a bumper sticker on my car and I put a small silver one that says rip city in the old school font on my rear window. That's about as far as I'll take it....... if you don't count my pinwheel tatt!
the worst thing about flames on a car, besides the 80's redneck appeal, is that the flames are too round. I like the ones that look like REAL flames. like this one: