Install is easy on the JGC if you have factory towing because there is a connector provided. Prior to MY14, the connector is down near the parking brake peddle. When I bought my P3, I also bought the prewired cable that had the Jeep connector on one and and the controller connector on the other. At that point, any installation time revolved around mounting the unit...about ten minutes for me. (The MY14 apparently has a Mopar controller becoming available and the integration points are up closer to the steering column)
Some folks don't prefer to position like I did, so in that case, they can use the connector pigtail that came with their JGC and the connector pigtail that comes with the controller and splice in whatever length of cable they need to put the controller where they want to. Some put it in the center stack lower compartment so it's hidden away when the little door is closed.