I haven't had any issues with mine, they hang down enough that they aren't tucked up under the cushion. I bolted a piece of 1/4" mdf to the seat frame, then attached another 1/4" piece for the actual amp to mount to. The purpose was to keep from drilling holes in the net looking thing. While it gives a clean look and gets them out of the way, amp tuning is a *****, and swapping amps is even more of a pain. Just something to think about before you dive in.
Before I learned about tech flex
My old PPI p1000.1 fit perfectly in one of the little areas under the seat but couldn't really fit anything bigger than that there. ***** because it was easy to swap out, easy to tune, and was still out of the way.