Sandpaper grit...

I have a 92 dodge shadow and the paint is peeling off. I heard they forgot the primer that year or they baked it wrong...anyways, I want to sand off the rest of the paint and repaint it but what grit should I use?

Check with a body shop. 80 grit is only used if you need to take down a lot of body filler, and I think you need to rough the entire car with 320 or 400 before painting. If the paint is peeling, you may find it easier in some places to take it off with a razor blade. It's just personal preference, really- if you like sanding, it works, but if you really hate it, there's an alternative.
Any bodymen here? Please reply- I haven't done this in a while.

if you are taking all the paint off, 120 diamond grit works well, wet sand if clogging is an issue. To prep for primer and paint, if you are using a high solid or two part paint, I would recommend Endura, it will hide a lot of imperfections, and lasts like the stone tablets.

I have had success prepping for Endura coatings, with 240 diamond grit, and a little patience. I have yet to see any of my prep work show through the final coat of paint.

Good luck, and remember, when doing sanding and shaping, wear a dust mask, and if using endura, its better to do your prep, then pay someone at a shop to spray it. Most good shops will flash the paint on fairly cheap, and they are set up with proper booths and breathing apparatus to handle today's paints. It's cool to do it all yourself, but it's not cool to be dead. Modern paints have some serious chemicals in there that are not real good for the lungs/ heart/ brain/ etc.

Enjoy