Quoted from Mitch:What do you mean by guide coated?
From what I recall from my auto body repair days in college, it's a light misting of paint, usually black, over the primer. Once you sand the guide coat off it reveals any imperfections.
"GUIDE COAT is designed to give the auto body refinish technician a visual guide to a smooth surface when sanding most primer surfaces and body fillers. It helps detect low spots, sand scratches or other minor imperfections in the repair."