I tried some Mopar F8 green powder from prismatic powders. Check it out.
Here is how I repair bad metal before powder coating it. I had a customer bring me an air cleaner once that was badly dented and had some bad rust pits. I have a special set of smaller hammers I use to tap and dolly the dents out to as close as possible. Then I use a marker like guide coat then block sand with 320 grit to see where the high/low spots are and to some more hammering. I actually top very lightly. Then I spread a skim coat of filler over the area. I use JB Weld; the original one (NOT the quick set). It is good for up to 500 degrees. Then I sand the epoxy smooth just like filler. I apply it sparingly, because cured JB weld isn't very easy to sand. Then I put a good, fairly heavy layer of zinc rich Powder primer on the piece and cure it at 400 degrees for 15 minutes. The powder primer is very good at filling in minor pits; I use JB Weld on larger ones. Then I block sand the cured primed with 220, 320 and 400 dry paper. Then I powder coat it. I can also cut out rust, weld in a patch and finish work the spot before powder coating. That air cleaner was a LOT of work. It was pretty rough. When all was said and done, I had about 20 hours in it.
That paint looks good enough to eat.
You could powder coat an entire car. I have seen powder coating ovens large enough to accept a car body. I could do the doors, hood, decklid, fenders and the nose piece in my oven, but I would need to find someone with an oven big enough for the body. The hard part is that you need to get the metal work REALLY good. It's not like you can use a bunch of filler and several coats of High build primer.
Here is how I repair bad metal before powder coating it. I had a customer bring me an air cleaner once that was badly dented and had some bad rust pits. I have a special set of smaller hammers I use to tap and dolly the dents out to as close as possible. Then I use a marker like guide coat then block sand with 320 grit to see where the high/low spots are and to some more hammering. I actually top very lightly. Then I spread a skim coat of filler over the area. I use JB Weld; the original one (NOT the quick set). It is good for up to 500 degrees. Then I sand the epoxy smooth just like filler. I apply it sparingly, because cured JB weld isn't very easy to sand. Then I put a good, fairly heavy layer of zinc rich Powder primer on the piece and cure it at 400 degrees for 15 minutes. The powder primer is very good at filling in minor pits; I use JB Weld on larger ones. Then I block sand the cured primed with 220, 320 and 400 dry paper. Then I powder coat it. I can also cut out rust, weld in a patch and finish work the spot before powder coating. That air cleaner was a LOT of work. It was pretty rough. When all was said and done, I had about 20 hours in it.