I think you should narrow your focus. Didn't craigslist start out with just one area? Why do you call it social classifieds? Is there a social network tied in somehow?
True, I've had some interest from some regional car dealers so definitely going narrower is an option. To really use the social features you have to be logged in and have a profile in mylistbite, but still want to expand the social network part. Also, trying to include it in facebook as an app which hopefully will give some traction.