First: What ever you don't want painted....remove. On Maverick's, this is easy, because they are easy to disassemble. If you need to leave some items on to drive it to the shop...that os O.K....just remove them at the shop. I know for a fact that Maaco/Earl Scheib will paint right over door handles, bumpers, key holes, etc (I have seen it done).

Second: I am terrible at telling you what "grit" sandpaper to use, I always tell the paint supply house what I am doing and they sell me the right grit. You want to sand the car (if the shop is not going to do it) and do a thourough job....especially around the edges and around anything you are going to leave on the car. These places tend to "scuff" the car down, but don't necessarily hit the hard to reach spots. I would concetrate on those....around the wheel lip openings, the door/fender edges, etc.