Matt, there is some cancellation, but nothing terrible. I ended up taking the fold down seat/armrest thingy out of the car entirely. The woofers are facing at about a 45degree angle inward. The "box" is shaped somewhat like a "V" , but the bottom of the "V" doesnt come to a point, it's got a small spacer to keep the 2 panels held together, sorta like a "U"...little hard to describe.

All together, it barely takes up any room, and gives me a nice deep thump.