Contemplating the purchase of this vehicle and wondering what to do with the factory HK system. So far I have Arc Audio 4200SE amps x 2, an Arc Audio 2150SE amp and will be purchasing an Audison BitOne HD DSP. I'm leaning towards the Hertz Mille 3-way system for front running active and Hertz Mille 2-way system in rear running passive. Need suggestions for an SQ shallow mount subwoofer 10-13".