1998 Toyota Corolla Part 3: Trunk, rear bumper rattle can paint job "wet sanding"

1998 Toyota Corolla otherwise known as the "Ole Work Horse" is having the trunk and rear bumper painted. Inclement weather, rock chips and flaky paint is what is left on this rear bumper and trunk. Fortunately, no rust!
First step is washing the trunk and rear bumper with car soap and a microfiber cloth. I use a spray bottle filled with car soap and water to saturate the metal and really scrub to remove flaky paint, tar and residue. Also, when it comes time to use a sander, I'm not grinding debris into the paint
The car was taped and masked off in preparation for painting. However, I knew some of the masking would be removed during the sanding process.
An orbital sander, sponge block, rubber block and hand are the applicators to get sandpaper onto the body panels.
180 grit sandpaper strips the paint off the body panel fairly quick without burning through the primer coat. Then I will feather edge the roughed-up areas with 220 grit and 320 grit sandpaper prior to spraying primer.