This is my first convertible so i know very little about caring for the top, but a couple of friends that have owned several convertibles over the years has told me the same thing....that there is more wear and tear when the top is stored in the down position. I think it has something to do with dirt rubbing against the fabric from the vibration when car is running. For now I'm keeping the top up when parked in the garage until I learn more about convertibles.