I'm actually trying this deal off in my trunk soon(just waiting for box to be made). I'm limited on what I can do to it cuz of MECA AS rules not allowing me to use spray foam or dutch tape. But I'm still going to trying seal off as best as possible. I'm gonna be doin it with 2 treo ssx 12" in an 98 Toyota camry. It's honna be tuned to about 31hz. It's going to be my first time trying this. The box is going to be more of an bandpass box due to my back seat opening to my trunk is only about 11h x 22w. With one 12 sub forward and port to side (passages side) I got best results(142.1 at 31hz at the head rest.. and was able to do mini hair tricks all day long). So with sub forward in MY car I liked it best... Hate rattles but thats just me.