Rattle can paint, when applied correctly (extremely thin and with many coats) over a correctly prepped surface, can do a pretty good job. I have put many miles on spray painted cabs with no sign of peeling. However, spray cans do not cover much and you will end up burning up a ton of cans. I think I used around 44 cans total (primer + Enamel + clear) to paint the cab of my current truck and I needed to apply more clear coats (decided to wait since I want to change the color). You may be surprised to find that properly mixed automotive paint isnt much more expensive than the rattle cans and at it's worst, will be on par with the best rattle can job.
Rattle cans also have a bad tendency to drip mid pass which is especially annoying when doing the roof since you cant take that off. I painted my hood on the truck and had to wipe the nozzles off between every.single.pass. to prevent it from dripping.