How about this:

To anyone Moderate-advanced at modeling

Subject: Photorealistic Car

Modeling- Preferably Polys, but if you really want to do it in NURBS go ahead

PolyCount- Try to keep it under 1,000,000,000,000,000 tris :p

Time limit- when someone replies, I will create a thread and we wll start then- and the limit would be a month.

Anyone up for it?