Fortunately for us, this car still had the original paint on it, which translates into THIN paint! A D/A sander with 120 grit paper takes it right off.down to the sealer. A friend of mine is a professional painter and says you don't have to take the paint off down to the metal, but only as far as you need for a good base. The original primer/sealer on BMWs is good stuff, so I had planned on just taking the paint off, but I noticed that the small nicks in the front of the car showed signs of rust as I sanded them down. Nothing to get very excited about, but the spots were wider underneath the paint, so you'll notice in the pictures that there are areas taken down to the metal. The more I work on this chassis the more I'm amazed at how straight it is. I feel lucky to start with such a good example.