I have a content website with message forums (unlrelated to cars)
but it generates me $200-1000/month just from people clicking Google Adwords and affiliate links, depending on the season (Christmas time makes the most money).
I also optimize my own websites to rank high in search engines to get natural unpaid rankings and visitors.
I can tell you if someone copied my content I'd be very pissed because:
#1 they could potentially put ads or affiliate links on their website with my content and therefor steal my ad revenue
#2 when search engines rank websites, they do not tend to rank duplicate content (for example 500 websites that are spammy and all have the same content or sell the same stuff... only 1 will rank high and the others get booted out or pushed down really low). So if someone did copy my content and Google or Yahoo or whatever thought I was not the original creator of the content for whatever reason, I could potentially get a duplicate content penalty and lose my rankings and traffic (and revenue).
Let me tell you if you want to make a content website and somehow monetize your traffic, all you can really do is get a very high quality website with unique content, get the content listed in search engines and ranking well for highly trafficed search terms, put up some ads or affiliate links (call up HPF or Summit, I'm sure they have an affiliate program) and then off you go. It's not as easy as it sounds though, and for supra-related products/content and possible revenue from ads/affiliate commissions, you're not going to get rich anytime soon

So you may want to try another industry that gets more visitors and clicks or perhaps just stick with making a supra hobby website.
Good luck!