Doing a whole car with spray cans is asking for trouble. I've done some bumpers for late model cars and that was pushing the stamina of my fingers. These were cans with more paint in them than consumer spray bombs, made for touching up car panels and the like. It's lasted almost 10 years and with some 2k clear over it, it's done better than the factory paint too. But the thought of doing a dart with them makes my fingers cramp ip just thinking about it.
Get a spray gun and start with some recommended settings. They're not hard to run. Cleaning them is a bigger pain than anything, and that's not a hard task either. I've sprayed a few cars with smaller 30g compressors (cheap craftsman unit). I had to drag my feet a bit to let the compressor catch up here and there, but it came out decent.
Oh and no matter what, get some respirators. Breathing paint fumes almost killed me in college.
