How to politely refuse a friend to drive your car without hurting feelings?

Even if your friend knows that you don't want to lend him your car, you should make up some good reasons to make it easier for him to go down the stairs. I usually say I need to use the car later, and then say sorry to each other. To tell you the truth, I really don't want to lend my car to others. I borrowed it once before, and he scratched my new car. As a result, he didn't even tell me. He found it himself. Whether he knows that the car was scratched or not, I paid for the paint myself, and now I still feel distressed.