Factory colors in a spray can - is clearcoat needed

[hillcountryflt]

My truck will eventually be primarily Ford Mallard Green. I am contemplating how I could paint just the cab roof, down to the doors Ford Seafoam Green (these two colors were on my first pickup a 1972 F100 Ranger XLT). As part of that accent I am planning on painting my wheels Seafoam Green and the lettering on the tailgate. Eventually, I will find a paintable grill and paint it seafoam green as well.
I found a company offering my colors in spray cans, but it specifies I will need to clearcoat it as well. I was planning to just sand, prime and paint the wheels. Do I need the clearcoat? Of course they offer a clearcoat in a small spray can as well.
A pro will likely do the truck. But some of this smaller stuff I will do.

[tac]

I guess they need it for gloss or to toughen it up. Or they may want to sell more paint.

Have you tried these guys?

http://www.automotivetouchup.com/touch- ... t/buypaint

I think it's laquer so if its not a metallic you can always buff it it until you need more.