I applied PPF to the standard high risk areas when new (Hood, front bumper, front fenders, mirror caps, trunk luggage area, and rockers). While washing the car recently, I noticed that the lower part of my front doors were getting hit. I'm guessing the 20" sticky tires really kick up the debris. My car is MSM and the chips are a white-fish color and this was only going to get worse. I had the bottom of the doors (cheat line and below) covered to minimize further paint damage. Those of you that sprung for PPF with 20" wheels may want to inspect that area on your cars as it's easy to overlook or assume it's just dirt.
Straight on:
Looking toward the rear:
Straight on:
Looking toward the rear: