While the renders look nice enough, I really still have trouble seeing the point. You have all the proportional guidelines with the models already, why not bite the bullet and learn modeller (if you don't know already that is) and build a good hi-def model? Rendering realtime models is slightly lost on me as low poly models of this nature only really look good when in motion and this hiding any poly shortcomings they have.
Go on, you know you want to, build a hi-def of this car, and then render it like these
Cheers!