i just finished a flat black finish on mine. I didnt remove too many parts, just tail lights, and little odds and ends. But let me tell ya from personal experience, DONT CUT SHORT ON THE SANDING! When i did my half doors, i sanded the gloss off one, but not on the other and started painting. The one that i had sanded the gloss off of looked 5 times better. Get that gloss off, and fix any rust, dont just take the easy route and spray over it. But i probably spend a total of about $60 on paint for my yj going from red to flat black. And like twoponchos said, if its done good, noone would guess its from a spray can.
~Paul