Here is one to do with ball cups. I went racing this weekend and had a real problem with the ballcups popping off. First I found if you pop one off you should replace it. Next for a tighter fit place a square of plastic baggy underneath the cup(got this from a magizine). Also if you are tired of losing all the foam washers just get some #60 or 1/4x1/8x1/16 inch o-rings and use them instead.