If you choose to do the job with a DA or other machine, just make sure you keep it running flat against the surface, don't push too hard, and stay away from any corners or body lines. You will need to do those areas by hand. Oh yeah, and don't be afraid to burn through some paper. Buy a box (50-100 sheets) and plan on using it. Many a good job has gone to hell from trying to scrimp on abrasives.
If you are going to wet sand by hand, make sure to not use your hand on the flat areas. Buy a semi-firm foam sanding pad and use it to keep your fingers from digging into the surface.
Good Luck!!!