Doc mentions that the DeLorean was more desirable because of its stainless steel exterior helping out with time travel somehow. I can't imagine how, since a regular car would be just as conductive under the paint, and the stainless steel of a DeLorean is on top of fiberglass panels.
Interestingly enough, Houston has a DeLorean factory up and running. They take old DeLoreans, strip them to the frame, and rebuild them from the ground up. They have brighter headlights, more powerful engines (and speedometers that go to 140 mph and mean it), better brakes, better electrical and hydraulic systems, better suspensions, new leather interiors, and you can add custom options like GPS navigation, an iPod jack, etc.
I've always wanted a DeLorean, especially an '81 model with the seperate door for the gas tank (meaning you don't have to open the trunk/hood to access it like the '82 and '83 models). Unfortunately, the old DeLoreans go for between $8,000 and $12,000 depending on condition (way out of my price range), and the remanufactured ones cost $45,000.