Oh heck yeah, lots of prep work:
Thoroughly clean both sides of the panels, fix any bends/dents/dings - sometimes requires multiple passes of filler primer and wet sanding, polish the stainless steel bezels, tape the front sides of the bezels. If the back sides have any surface rust: remove rust with light sanding, tape back sides of bezels, primer the back sides.
No sanding on the front sides until the bezels are taped and protected. Wet sand front sides, primer paint, wet sand primer, repeat as needed, color coat paint, wet sand, usually repeat at least once, apply clear coat, very lightly wet sand to remove any dust - just a kiss with the paper! Untape the bezels, wipe down with soft cloth, grab a beer to celebrate!