I've had incredible success with
This Stuff Comes in a variety of colors, levels itself out very nicely and the stuff is bulletproof.
They make it in rattle can form, my brother in law used it to paint one of the tractors at the plant, and it held up just as well as my paint brush '46 1/2 ton.
$8 a quart, or $21 a gallon. Using a brush, I think I needed all of two quarts to paint a '46 1/2 ton cab and bed.. so $16.
Having painted several vehicles in the past with a variety of rattle can paints, I can honestly say I haven't ever seen anything else in a rattle can come even remotely close to the quality, look, and durability of this stuff.