Sites like camaroz28.com and many others have had actual pictures of cars for years. Putting cars on cardomain would be infringing on copyright then, if you think about it. Your not making any kind of profit off this site or the use of those pictures are you? Besides, GM does not own my car, I do. I say go with something that has cars on it.
btw for the last one, the site is .org not .com