Question About Getting A Newly Bought Used Car Home

Well Oppo, you may soon be looking at (well looking at the typed words of) the owner of a 740 Turbo wagon. There is just one question that I'm hoping you can help with. Currently, the seller doesn't have the car registered. It has no plates or anything since he transferred them to his new car. So, how do I get this wagon home if I buy it? Am I better off putting an old Florida plate that I have lying around on, or do I go to the DMV and try and get a temporary or risk driving without one? Thanks for the help since I've never done this before.