in my saph i have a alpine V12 amp boxed and mounted to therear seat, and a 10" free air sub in a nice custom built parcel shelf, which isnt MDF, i dunno what wood it is but iit weighs a fookin ton. I also have some rear componets (JBL) in the shelf which run of the amp, and them metal pioneers compnents running at the front, the car used to be owned by a car audio shop as a demo so the install is pretty good quality and the wiring is top notch as well. The best thing tho is i lose zero boot space which is quality