$5870 small parts paint booth

Or less than $20 if you deduct the cost of the finishing kit. I'm sure I'm not the first guy to turn a van's crate into a downdraft paint booth, but mine turned out pretty good, so thought I would post a pic. Fan was $7 sale, chicken wire was left over from my wife's garden. Time to cut the crate in half and modify it was less than 2 hours. When not in use, I'll throw it on a furniture dolly and wheel it out of the way.

Boothmaster 9000! nice!

steve, you asked for armchair experts by posting!...so here it is.

light; paint the inside white, or staple up some scraps of white coroplast, that can be swapped out periodically..... wouldn't hurt to have a lamp at the top back edge so you get a little shine on the wet paint surface.

make a second wire-mesh tray, so after you shoot the first batch, you can carry it out to dry, and shoot a few more without getting overspray on the first! Old oven racks even work for that.
you'll want to add lots of hooks & nails, so you can hang your gun, rags, tack cloth, jug of prepsol or whatever.

be sure to open the door at your back, so you actually get some airflow thru the thing.

Wardrobe Boxes

I've also hung parts in movers wardrobe boxes for painting.

I did the same but with the fuse kit box. Added two 20 in box fans. Works great