OMG Jim, you bought stuff from Benzbaron and **************. Traitor!!
I sold a car one on Ebay. Didn't get a really great price for it, but the car was a dog anyway. I met the guy at the airport, he paid with a certified check and drove the car out of state. I trusted him with the license plate on the car, he said he'd send it to me, and of course I never saw it again. Good thing I didn't need that plate anyway. I also got lucky that the check was real and not a fake.
Lessons learned: verify payment and make the buyer do the DMV stuff.
I also bought a car advertised here on Mercedesshop (240D in my signature). New York DMV was a royal pain requiring 3 trips and numerous phone calls and faxes, but the seller was fantastic and we got it all done.