When I picked up my '99 from the dealer, the paint was really "grainy" from sitting at the lot for soo long. Anyways they buffed some of it out, and now I want to get the rest off.
I have Meguiar's Polish - should that take care of it?

I believe the rough surface is from the weather and dust.

 

Sounds like you have industrial fallout embedded in the paint or wax. You might want to try a clay bar.

 

Definately clay bar. I bought my used '99 off the lot a few weeks ago. Surface felt rough. I tried to wax it, and moments after it dried to a haze, I thought I'd never get it off. Man, that was work. I have since used a claybar (roof was really bad), it feels like glass.