Lows are the most common and can be caused by many things such as: Door dings.. Basketball hitting car.. Rock on the highway.. Sitting on the hood.. Mechanic leaning on fender.. Before After Highs are less common than Lows, but can happen more easily than you think: Closing a hammer or wrench under hood.. Door speaker installation.. Broken class wedged on inside of door.. Window replacement.. Before After Creases are the second most common: Door dings.. Moving item such as a grocery cart.. Before After