At the January 2013 Bill Reider discussed and demonstrated "How to Photograph Your Car". The following is Bill's handout with tips on photographing your car. And, the pictures below show pictures Bill took at the meeting, the benefit of correct lighting, and results of photoshopping a picture
This is the car in the same location but using an indirect flash.
This is the car taken with a direct flash.
This is the same car picture after being photoshopped.