Rolls Royce Loan

A businessman walks into a bank in San Francisco and asks for the loan officer. He says he is going to Europe on business for two weeks and needs to borrow $7,000. The bank officer says the bank will need some kind of security for such a loan.
So the businessman hands over the keys to a Rolls Royce parked on the street in front of the bank. Everything checks out, and the bank agrees to accept the car as collateral for the loan. An employee drives the Rolls into the bank's underground garage and parks it there.
Two weeks later, the businessman returns, repays the $7,000 and the interest, which comes to $19.67. The loan officer says, "We are very happy to have had your business, and this transaction has worked out very nicely, but we are a little confused. While you were away, we checked you out and found that you are a multimillionaire. What confuses us is why would you bother to borrow $7,000?"
The businessman replied, "Where else in San Francisco can I park my car for two weeks for $20 bucks?