One Halloween when I was still in Chicago, I lived on Halsted, where the annual Halloween parade would go through (just drunk people in costumes).
One guy, driving his black Trans-Am, had constructed a fake steering column in the passenger's side dashboard, and placed glow-in-the-dark green skeleton in the passenger's seat, tying its hands to the fake steering wheel. He sat in the driver's seat, with a black shield over the real steering column and dressed all in black. I believe there were also green ground effects.
It was quite awesome.