For a 2011 fx4 with factory 6 disc radio, non factory sub. I've spent all this time installing speakers, amps and subs and have nothing to show for it. The Pac-Audio FRD24 I intalled only works on one door speaker. Checked everything. It's the harness. Their site shows it only work for up to 2010. I thought I read here that some guys were putting them on 2011 models with no problems.