I have used the clear 3M on several of my present and past cars.With today's new products and improved chemical technology,yellowing may be a thing of the past. Wash and clean the same as the rest of the car.Yes,stones may damage it,if they have sharp corners or edges and have a bit of velocity behind them.I've had the 3M take a couple of rock hits,but didn't damage the car,in my case.
