Looks like i'm going to have fun installing this..
since its an auto, there should already be an accessible hole in the firewall to run the power cable thru.
get the stuff and then we should be able to hook this up in no time flat..
tapping into the back speaker will give you bass.. but won't be as clear and proper as it would using the LOC, like was mentioned by Bryan.
Tha Kraken: http://www.focusfanatics.com/forum/ford-focus-builds-general-showroom/285082-meet-kraken.html