[EricH]

Originally Posted by JVN

That is my interpretation, also.

The undefined rigid fastening system can be a heavy, rigid fastening system, as long as no other rules are violated.

-John

Aye, but here's the thing: He wasn't asking about a fastening system. He was asking about a backing system. Now, to me at least, the way the question was put indicates wanting to put a nice large piece of metal behind the plywood, in addition to the fastening system. Not as the fastening system, but in addition to it.

So, here is a question for you to answer (and may you have the right answer as the inspectors): If there is a heavy piece of metal, that serves no purpose in the fastening system or the bumper, and it is attached to the bumper, is it legal or illegal? Assume for the sake of discussion that the fabric is clamped using an obvious system not involving said piece of metal.