I was carrying some parts the other day out in the garage and of course one of them had to fall out of my hands just as I was walking next to my Dart. It brushed against the quarter panel and in the process put a scratch about 5/8" long in the quarter. The scratch is deep enough that I can feel it with my fingernail. I am not very knowledgeable when it comes to paint related things but I would imagine the scratch is going to have to be wet sanded out as I tried using some rubbing compound on it and it didn't help much. I don't have any experience wet sanding so what I would like to know is, how do I go about wet sanding the scratch without risk of further damaging the surrounding paint? I had the car painted two years ago and the car isn't even back together yet.