Wire wheel work well huh! take some plain water & scrub off the rust converter, do it a few times, dry then sand again w/80 - 150 & your good to go. If its pitting try & work the water/brush down into the pits, sheet metal-should be a breeze. Then your metals ready for epoxy.

you can do the car in pieces as well - sand down to bare metal, prep properly then shoot that spot w/epoxy, move onto the next. If its in epoxy sitting outside wont matter as long as its out of the sun. Do not use a regular primer as it will allow moisture thru the paint, their not waterproof.

I'd suggest a small car cover for the dew, that'll help.

Spend time reading on the paint & body sites for technique & product info.