Trying to tackle painting my MJ..... never done this before and it seems super overwhelming. I have some panels that have really good paint, clear coat is still intact etc, and other panels that have faded clear coats with rust spots. The worst paint on a panel I have has paint flaking off from the primer, which you can see exposed underneath. I know for rust spots I have to sand down to metal and apply filler but for the paint what grits do I start at? From my understanding, paint that's still in good shape shouldn't need a lot of sanding so I should use a finer grit (600-800?). With the non clear coat/ flaking paint, I should start with a more abrasive grit (320?) and go to a finer one (800?). Is this the right approach?