you guys are crazy , and 80 grit is hnoes:

wetsand is tedious job and requires a lot of attention.

General Procedure:
1. Use fine sand paper, 1000 grit. Sprinkles water and sanding at the same time
2. Use a SOFT sanding block
3. Sand in a SLANT position. DO NOTUSE CIRCULAR MOTION.
4. Do it 1 sq foot area at a time.

But hell, if you want to repait your car, use a sanding machine, and sand it with some 800 grits. Touch up the holes and dents in the body (a whole other story). Machine sand it again, or if you want to becareful, do the wetsanding. Then primer it, then wetsand it again, then do the paint. When you're talking about hand sanding and stuff, you're talking about $5000+ paint job there where a person must pay absolute detail to every inch of your car.