My business is motorsports websites (well one of them anyway)...
So some thoughts: (And I'm gonna be brutally honest because being all touchy-feely won't help)
1. Lacks pizzazz. Front page is rather dull. Functional, but dull. Light blue font on white background not advised.
2. Style looks too much like spam. I first saw the page, I thought it looked like the website is a domain camper (ie sites that only link to other places hoping for click and search revenue). This might work for craigslist, but I suggest a little something more.
3. Lacks a grabber on the front page. Most consumers leave after 3 seconds if they don't see what they want.
4. You need a geographic (proximity) search.
5. In the course of doing a few quick security checks for you, I attempted to find your administrative page. In the process, I noticed that your 404 page redirects to a domain camping page where your hosting provider is probably making money off of you. Since it's a domain camping page, it kills ANY credibility you had with the consumer.
Try it, go to:
http://www.motolist.com/xyz and watch the spam come up from your hosting provider.
Just a few quick thoughts. Ping me if you want to talk about it.