Bed mat and cutting out for factory bed holes?

JRscooby wrote:
Do the pucks have threaded holes? If so, cut head off bolts and screw them in. Tap cardboard or mat (plywood?) with hammer, this would make marks for center.

No threaded holes. Just big key like cutouts. The frame fits into then you turn the key. It spins and locks it in place. But after hauling the camper 600 miles. There's perfect marks in the mat now to cut out the holes.