pretty much self expanitory you use a very fine sandpaper that is wet. used for imperfections in paint like fish eyes or orange peel usualy. if a paint ids very heavily oxadized they will sometimes wet sand the finish and then buff it out to a nice shine. but on a car as new as ours there should be no reason for wet sanding when detailing
Wet sanding is using a fine sandpaper (1500-2000 grit) with water.
If you're dealing with fresh paint, wait a few days for the part to cure and wet sand it with 2000 grit. This will remove any small imperfections and orange peel. Buff the part out either by hand or via machine (orbital buffer) with 3M Rubbing Compound.
If you're thinking about wet sanding your paint on your car, I'd recommend a paint gauge and check how many mils your clear is before doing it.. I would sure hate to break past the clear considering how thin it is from the factory.
MOST wetsanding is done PRIOR to a paint job, on a primered and filled car. You have done all the rough sanding, all the body repair, and added a second coat of primer, and then used a guide coat for finish sanding. THEN, a final primer coat is applied and the entire car is wet-sanded with ultra fine sandpaper or emory cloth. Once this is done, the surface should be free from any imperfections and the paint should be perfect as applied, provided the guy spraying it has a clue and 20 years experience. Usually only the cream of the crop gets the wetsanded treatment, but it used to be a common practice for most street rods and classic restorations. Prevents a lot of the post-paint work of buffing, sanding, buffing, etc.....