I read some a lot stuff about how you get weird reflection canceling in the setup against the back seat firing backwards, and you really want to place it all the way in the back facing forward, which was why I wanted to run dual 10's in fiberglass boxes molded for the rear corners. Personally I had the setup with the box against the rear seat facing backward for years and it always sounded fine, but I've always been running low-midrange equipment like Fosgate Punch, Cerwin Vega, etc, so it may make a difference using better equipment like what I now want to use.