ORIGINAL: honeygoldcoupe

Kilgorq is right about the sanding pattern. Generally I use 80 grit, then 100, then 220 and finally 400. When you are finishing it, use a very light touch...just enough to take out the marks from the heavier grits. And in a lot of areas you simply can't use a block (compound curves). When you use your hand try to use your palm and not your fingertips. Your fingertips pressing down on the sandpaper will leave grooves. And I think Kilgorq meant to sand it after you spray a little paint on it. The block won't take the paint out of the low areas and you can see them. I actually use primer for that. And one last thing...a common mistake at first is to use too much hardener in the mix. It does not take much, as is evidenced by the tiny tube of hardener you get with a full quart of Bondo. The Bondo brand comes in several quality levels and I spend the extra couple of bucks for the premium stuff.