[hardluck]

I used a DA and some 80 grit lightly on my door panels, and hand sanded the areas I couldn't get with the DA. You have to be careful not to burn and warp the plastic, and to clean the crud off the paper often. After the DA, I hand sanded with a wicked-thin pad until the panel no longer looked like Tommy Lee Jones' face, then I switched to 320 grit, went through the same motions, then used an automotive primer and paint gun. After that, I used my thin pad (to contour the curves in the panel) with 320, and carefully began sanding the primer 'til the whoe shebang was smooth as a baby's ass