It doesn't really matter if the paper is wet or dry..
But definatly get some 1000 grit min..
Depending on what brand of paint you use, you'll probably have to clear coat also,as the excess fuel will melt your paint...
Definatly don't waste your money taking to the body shop..
Who cares if the paint looks a little crappy when your done.. It's not like anyone will be saying "paint looks orange peely" as your hooking past them...
O.k so i'm a noob to this site and didn't read the 3 pages inbetween if i covered what others said then carry on..