Andy, the key word in rule Gary cited is not "fastener" but rather "bracketry." Bracketry (or even "bracket") is not defined in the GCR.

I would argue and believe that any piece whose sole purpose is to hold in the passenger seat can be removed. How it is attached to the car (whether it be by nut, bolt or spot weld) is irrelevant.

Kirk, yes, I suppose this is an aggressive interpretation of the rules and I probably personally would not do it, but if that parapet wall thingie is only their to attach the seats -- in my view it COULD come out.