[Smells like art] You can make an art car!
The 'art cars' I've seen have little to do with art, and a lot to do with glueing pieces of crap all over your car, but God bless those freaks one and all, I say. Maybe yours will be better. Its a wide open genre.
"Consider using props, sound, light, and maybe even smell as your design your car's personality."
Smell?! Bring it on, baby!