anybody used this? I´ve got a friend with one (hasn´t used it yet) and my escort is very very dented all over, and I wanted to know if this was a good tool, or a bunch of bullshet. I don´t want to fatigue the metal or anything and I don´t want to create any cracks where the body will rust through or anything. I just want to sortof take out the dents a little and make them less obvious. thx