Unless you have your dealer license you will have to register and pay sales tax on the Contour. Then there are the problems of insurance coverage and test drives. If a customer has an accident while on a test drive, you could get sued.
I sold my dad?s station wagon and I had some really stupid people to show up for test drives. One elderly woman got up to 70 MPH on the highway before looking at the controls. It was like she had to have the car up to 70 MPH before she started to inspect the controls. She kept drifting across the center line and almost hitting cars head on. I let her take the car to her mechanic for inspection and she offered me half my asking price. I finally sold the car for what I was asking but it was time consuming and not very much fun.