Get a angle finder. Find the angle of the rear seat, get some 1/2" MDF and build a custom amp rack. Itll look alot cleaner and be sturdier. Their are some braces but nothing big enough or close enough to tie a amp into.

That'* where the stock BOSE amp is mounted in the 2000+ Bonnevilles...right against the rear trunk wall behind the back seat, but hidden by a plastic protective cover. The On-Star system is monted back there, too.

I have plastic on the back of my back seat. and I have my XM tuner, and one of my amps screwed into it.

Rob