DEAR HARRIETTE: I am in a tricky situation, and I’m not sure how to handle it. Recently, I borrowed a friend’s car for spring break and went out of my way to take good care of it, even going as far as getting the oil changed because it needed it. I left it in perfect condition, and yet, when I returned the car to my friend, they tried to make me pay for damages that were already there! I feel tric…