dumb question

I pulled the back seat out , trimmed .024 steel to fit and used silicone sealer where it is riveted to the stock cross bracing......if you cut out around the seat mounts , it pops right back in with no problems.
I used a GM product called seam sealer on the sides and bottom.
I think between the silicone and the seam sealer , the vibration noise should be minimal.
I mini tubbed the car , so there was a bit of trimming on the lower part of the seat too , but it looks pretty close to factory once it all got stuffed back in place.
Lay a thin bead of silicone on the cross bracing and let it set , then seal the edges once you get it riveted down.......... piece of cake.