You shouldn't use 2000 grit inbetween coats of paint or clearcoat. It is great for final clean-up and wet sanding, but will make the surface to smooth for the paint to "bite".
Go 800 grit between coats to give the paint something to adhere to. That is, if you need to eliminate Orange peel. You may not even have to sand if the paint lays down nicely.
Oh, and one more word of the wise...
PATIENCE!
I've F***ED up so many jobs becasue I was to damn impatient to wait for the paint to dry/cure before I touched it, or put on another coat. Let the primer set a good few hours in the sun before you seal it with paint, and then let the paint cure at least a day before youy lay the clearcoat out. Otherwise you are sealing in the gases that want to escape from the underlayers, and that is when you get bubbles
