Scratch paint off doorjams all the time. I try to be careful around cars, except when they ding my door or park on the bumper. Then I don't pay attention to where my clip hits. I haven't damaged any clips yet, but two friends who don't read this board have. One bent his Police clip way out, catching it on a doorframe. The other caught his Endura clip on something (I can't remember what it was) and messed up the zytel. He wasn't too pleased about that since it was his first Spyderco, and he's not a knife knut.