i sprayed some sealer on the inside of my truck's cab and it is my last coat before i spray the color... however, i put it on especially thick, so after a few minutes, the paint had some slowly-forming runs in it. should i use some rougher grit to get the runs flatter before i wet sand the whole area or would it be a risk of cutting too far down? i really dont want to have to put another coat of the paint on before i shoot the color, so i would really like to just sand out the runs... any suggestions?

use a good fine grit for initial wet sanding to get rid of the runs and then a super fine grit for the final wet sanding to smooth out any marks left from the first round.

He is right, i would never use a rough grit for anything that close to the final coat. It would cause tiny scratches that you probably couldn't see until after you painted it with your color.

thanks for the advice, ill try wetsanding the runs with some 600 grit i have laying around before i use the 800 grit on the whole thing

You might want to use 1500 once before you paint it if your are worried about it looking 'smooth' enough. But 800 would work if it is not that big of a deal.