Car stereo guys do work like this all the time. Its absolutely not for mass production since the whole idea - which car, what woofer, how much space, etc- is custom to the core.
I did one exactly like this for the back of my Honda many years ago. Incredible deep bass, which it turns out is not all that hard to do being as its a car, small sealed space, etc. Search around, you will probably find everything you need to know from how to design the sub to how to make and install it in the car, on youtube.
I did one exactly like this for the back of my Honda many years ago. Incredible deep bass, which it turns out is not all that hard to do being as its a car, small sealed space, etc. Search around, you will probably find everything you need to know from how to design the sub to how to make and install it in the car, on youtube.