Now both of the C pillar base plates are welded up solid and I can now weld in the tubes for the rear seat mount in place. All of the tubes for the rear seat mounting are bent and notched and are just waiting on the tube clamps to be welded and the welding on the base plates to be complete.

Since the seat mounting tubes weld to the cross bar between the C pillars, the base plates needed to be welded so that the cross bar can be tacked in place.