oh HONU,
World of Wheels is like a huge car show. They have it everywhere. If you want to try to work for them I don't know how to get you in, but to be a vendor you have to pay some fee, then set up at the show and try to sell. I haven't had much luck at car shows selling art as I'm not an airbrush guy, and I don't stock up on prints or giclee's. If I was to do a world of wheels show I would take my little photo portfolio and some cards and try to talk to the owners of the cars. Chances are they or an organization they are in might be interested.
In my opinion most people pay the entrance fee to look at cars, not buy art, but most of the people who have egos and wallets big enough to have a car in the show have egos and wallets big enough to buy art of the car.
Target your market and jump in. It takes time to establish a foot hold, but stick with it. The worst that will happen is they will tell you no, and you keep trying and they say no, and you keep trying. Eventually you'll look up and be good, and someone will say yes......then to quote South Park....It's on!
-Lemorris