A question for the rattle can guys

[hpcgmc]

I just rattled can painted my whole truck in primer gray. I used primer because I intend to get the truck painted in a year or two, and this will make it look presentable while I work on suspension, engine, etc. This is my first major foray into paint of any kind, and especially a full vehicle rattle can. I don't want to spray a top coat of a finish spray paint, as I was told at a paint shop that this would make it much more difficult to paint when I'm ready for the real thing.

The primer scratches pretty easily, seems to rub off pretty easily, and seems to hold dirt and greasy hand marks. Should I try to wax this to keep it from rubbing off and resisting scratches? If I wax it, should I go over it with a very light sandpaper first?Should I just leave it as is? Here are the before and after pics. I'm pretty happy with how it turned out.

Thanks for any ideas.