What is the missing number i...

It was a small town and the patrolman was making his evening rounds As he was checking a used car lot, he came upon two little old ladies sitting in a used car. He stopped and asked them if they were stealing the car. They said "Heavens no, we bought it."
He said, "Then why don't you drive it away".
Each of the women said "We can't drive".
The officer momentarily shook his head and then asked "Then why did you buy it?"
They answered, "We were told if we bought a car here, we'd get screwed, so we are just waiting.