i have a spray can flat black paint job.....does anyone know if i spray it with a coat or two of high gloss black if it will look good?

i really dont want to sand down the paint....im just looking for a cheap job.

 

Should be fine bro, that flat black can be used as the primer.

 

Clean the surface well & yeah, the flat should act like a primer. A Scotch Brite pad & a good rinse or tack cloth would better the adhesion IMO.
A lot depends on the surface & your paint technique, overlap, runs etc. More light coats are far FAR better than a heavier coat. Google paint techniques & apply what you see to your application.