Master Fwiifo has found an interesting link to SAABHistory.com that says the SAAB Aero-X concept car will be making it's way into Transformers 2. Moreover, it says that there's a possibility that it could be Transformer! (And not just that roof thing) So who could this car be an alt mode for? There is a name mentioned, but you'll have to click the link to find out!

Click here to see the original article and here to discuss it in Master Fwiffo's thread. There are, of course, potential spoilers in both links.