I went to autobody school back in 1983, but retired due to bad health. I still have my Sharpe siphon gun. lol
I built and painted my Cobra in 2001, at the paint shop my brother-in-law worked at, but the owner put a stop at that and he even makes the employee's pay for the booth time !
It also would make me rebuild my old leaky Binks filter/regulator that is 35 years old, or replace it with a modern system. I love to paint, so trying my hand of a new Devillbis HVLP guns. They have a 2 gun start or finish line system that are pretty nice guns. I wouldn't paint a entire car with them, but for my needs which includes DIY home products, they'll be fine.
I checked out the rattle cans and bomb type but, I can't find a matching color, and if I had my local auto body supply mix several cans for me, that can get expensive too. Plus, you'll never cover the material thickness of a paint gun. I painted my engine and bell the first time with just a single stage paint and 10 years later, it still looked great when I sold it. Using a base system, the clear will brown up because of the heat.
I insulated my garage very,....well, so when temps are even single digits outside, I've never had my garage temps lower than 37° or so. My infared propane heater works very well, but I'd must be done painting by late evening as I would never run it over night. To heat up the parts and to help bake-in the paint, I 'll use our sprint car engine heating blanket.
I can also use our portable dehumidifer (don't tell my wife) if needed for heated -air grain drying.
If,.....everything works out with my health and temps, I should get the project done in one day. Just wish I could wait for much warmer temps,.....but I can't.