I know Bumble bee is going to start out as a 1971 Camaro and then rebuilt as the 2009 camaro, Optomus prime is a Peterbilt truck, Barricade is a 2006 Ford mustang police car, Ironhide is a GMC Topkick C4500 4WD Crew Cab Pickup, Jazz is a Lamborghini Murcielago, Sarscream is an F-22 Raptor, Vortex is a MH-53 Pave Low Helicopter. And Ratchet is a Hummer H2

Heres some links with pictures
http://jalopnik.com/cars/transformers/?
http://www.tigerdroppings.com/rant/messagetopic.asp?p=2630276
http://www.leftlanenews.com/2006/05/31/new-chevy-camaro-to-star-transformers-movie/