I am thinking of making a set of head rest for my 66 seats. My plan is to use large diameter pvc pipe with end caps to form a base. cover that with padding and vinyl. The supports will be steel rods? maybe, or what ever Home Depot (a new one just opened 3 miles from the house...YES!!!) has that looks right. They will attach to a steel plate on the inside of the pvc. To attach it to the seat, I thought about pulling the back, and spot welding steel pipe with the same I.D. as the O.D. of the supports. This is still in the planning stages, any thoughts? Anyone done anything like this before?