The 14 year old factory sub (non-Bose) was thoroughly rotted out and effectively just making noise. After looking around for a shallow mount DVC 8" sub I selected the MBQuart based on price, design, and construction. Many online sources for how to get the sub out so I won't elaborate on that. I found how to wire the MBQuart to be 2ohm impedance, removed the old sub, and the MBQuart fit the stock sub box perfectly. The sound is much improved, especially coupled with a new HU and front speakers. Also, don't forget to implement the "amplifier" bypass when upgrading the front speakers to get full range from the new fronts.