my amp has been mounted to the back of my box since it was purchased like four or five years ago by my friends father and he always cranked the **** out of it when his father gave it to him and then I always used to crank it real loud when I first bought it to and it still hasn't vibrate loose any internals. I think thats only if you have ridiculous bass
custom designed/built box. pretty complex shapes and angles but the outcome was a perfect fit for the shape of the trunk, zero wasted space behind the box, literally slides RIGHT up to the back of the seats.
picture of how my mock-up box fit against the back... dont have pics of the actual box from this angle.
the only thing i have mounted to the backside of my box are my crossovers for the front speakers, an amp wouldnt fit in the space left there.
