A thought that I'm currently looking into as an alternative is building a sealed enclosure under the glovebox. There's enough space to get about a .8cf enclosure under there without taking up too much of the passenger's leg space (besides, these cars have tons of room, just move the seat back). I'm looking into putting one high x-max 10" sub with plenty of power, then putting tactile transducers on the seats to add that "thump factor". I am a busy musician and regularly have to fill up the cargo area with equipment and pulling my 12s out every time is getting pretty tiresome. I dunno, just another thought for you! The mdf to build the enclosure would be <$30. If I do get around to making it happen I'll put up cut measurements, diagrams, pics, etc.