The trick for paint jobs that don't look like crap is to pay the money for the decent rattle-cans; not the 99c enamel from Wally World.
Depending on application, I use either Martin-Senour epoxy paint or Krylon urethane in semi-gloss finish. And at least 2, preferably 3 or 4 "mist coats" allowed to dry hard before the final coat. I've made more than a few custom panels out of 0.30-0.60 aluminum. Then a final coat in clear semi-gloss or my favorite, semi-matte finish.
The problem is trying to match factory paint; equipment like ours comes in custom colors, and unless you want to go to a paint store with a paint chip or can find the legacy Pantone number for your gear, you're not going to get the right color; not even close. It's infuriating, actually.
You CAN get a decent finish using these paints; but you have to be willing to accept that you aren't going to get the right color.
mnem
*Spray paint-ily*