I would not spray clear over the paint if a hardener was not used, there is a chance it will lift.
The cheap paint I am thinking with the hardener will hold its gloss better without clear, but my experience with cheap enamel and no hardener isn't good, the paint never fully cured and could not be sanded. Had to be removed with paint stripper and razor blades when it came time to repaint.
A buddy of mine paints every car he builds with hardened rustoleum and mid grade automotive clear, they look great.
I paint my frames and did the inside of my cab on truck #2 with Tractor supply Valspar and hardener, then did the dash with automotive clear and metal flakes. Worked great and no paint lifting. I got the paint on clearance when TS was switching from Valspar to Magic, was around $15 a gallon.

 

Bob no problem with the hijack.i had a lot of people so far say that they like the color and ask what is it.well since I developed it myself I figure that I should name it so I tell everyone that it is " HILL BILLY RED", so what do you think ?

 

I Like it!

 

I'm not a big red person, but it looks good in the pics!

 

Here is my meadow green. The cab was (is) is original meadow green. The 9' bed was a silver blue metallic so I mixed some rustoleum hunter green, Their flat black, flat white and rustoleum horizon blue. Painted it with a foam brush. I think it is fairly accurate. I used flat for the black and white to simulate the sheen of the cab. Gloss would make it shiney if that's your goal.