Funny that you guys talk about finding the right woman who will understand your love of cars. I am having the same problems with my man. I find the best way to avoid the issues about spending money on cars is to just not tell him what I bought that day. As long as he doesn't see the bill, he doesn't care.
Also, I've gotten quite a few marriage proposals from guys who keep saying that it's rare to find a woman who is into cars, home theater, and computers. I just wish my husband valued those traits! Oh well, it's not so bad. At least he doesn't mind if I have my toys.