If I come off sounding disagreeable/hard assed, sorry, not the intent.
The bottom line is that the site is already growing on its own. There have been quite a few members added int he last few months. I don't know if having a site sponsored car would increase the membership all that drastically.
On the other hand, getting sponsorship will be equally difficult. Not that there is anything wrong with the F, M, J bodies (there is a lot very right about these cars, but I am biased0, but the aftermarket has not yet come around to supporting the cars in any meaningful way. There are some suppliers that do make parts for our cars (Firm Feel, Autorust, Schumacher, a few others), but I don't think that the sponsorship dollars would be there to build a competitive car. I am also sure that any vendor would see a larger site (For A Bodies, For B Bodies, etc.) as a better way to spend sponsorship dollars.
As for getting a bank loan for this venture, I don't think, in today's economic climate, that banks will be very inclined to loan out money to build a race car, without serious revenues coming in.