two little old ladies

Police Officer O'Leary is cruising around in his patrol car one night. He is on the lookout for trouble.
He sees two little old ladies in the front seat of a Chevrolet convertible, parked in a used car lot. The car lot is closed so O'Leary drives up alongside the Chevy and asks, "Are you two ladies trying to steal this car?" "Certainly not," says one of the ladies, "we purchased the car this afternoon."
"Well," says the cop, "why don't you start it up and drive out of here?" "We don't drive," replies the other little old lady.
"And besides we are waiting... We were told that if we bought a car here we would get screwed!"