HELP with bodywork

400 wet, is like 320 dry. 320 with cheap lacquer rattle cans = very bad shrink back and sanding scratches that will be visible from the next state over. You'd have to spray it, sand it, and then let it sit in the sun for a month, and then do a second coat, sand it, and then let it sit in the sun for a month, etc..... and then you better hope that whatever topcoat you have put over it doesn't have an adverse reaction to the cheap lacquer and lift it off in sheets.