Sup man?
If I ever decide to tune to 30 hz, I have a cool super space saver design in my head. Picture only a third of my trunk taken up, and the sub reverse mounted whereas the basket/magnet sinks into the right rear quarter panel, and an aero port exiting the rear towards the trunk with something like 3 inches to breath. I think about building it every time I have to put groceries in my back seat lol.
Edit: it actually is just like that Alpine space saver box above, but with the sub reverse mounted.