Two humorous stories...
I decided to buy lunch for the my co-workers the last Saturday. There are three of us that work in the parts department on Saturday and I had been treated to lunch more than once by my fellow workers. We have a small teriyaki restaurant in a strip mall next to the dealership so I handed one of the guys my Discover card to pay for our order.
One morning this last week got a call from a customer upset because their car wouldn't start. Really upset about the fact that they had purchased this new car so it would be reliable and start. They had the vehicle towed into the shop and were extremely upset at the counter as the service advisor was writing them up. He handled the situation, got them a loaner car and as they were walking out the customer said, "We had an interlock installed." The advisor asked when and the customer stated, "Yesterday."
They apparently didn't understand how it worked.