install on 04 BMW X5

Has any one done a sub amp install on the new X5's. looking for factory amp location, i dont know yet if it is the Harmon Kardon system or not. How hard is it to get through the firewall, where did you tap wire for an LOC? Any info on this would be great, this customer is very picky and a jerk to boot, so the more i know about the car the better. THanks in advance Jazzy

If its the HK system I am almost positive the amp is behind the rear passanger quarter pannel in the hatch. As far as the firewall goes I honestly dont know, but is a beamer so its likley a bitch, sorry. As for tapping the speaker wires, if its got the hk amp and the amp is where I said then get your signal there, if not either tap in behind the deck or see how hard it is to get directly to the rear speakers, it might be easier to just go strait to them.double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer