We used to remove "hail" damage from car roofs,hoods & trunk lids by using dry ice. On a very hot day late afternoon when the temprature is at it's highest.Place dry-ice on top of the dent when you hear a pop the dent should be removed.This will not work on a dent that has any kind of crease in it and on some dents it will not work at all. The dry-ice must cover the whole dent. p.s. use very thick and well insulated gloves when handling dry-ice it will burn you severly in seconds. Hope this may work for you. ;R.D.