Just bought a 2014 GC Limited with nav, 20" wheels, tow package and upgraded stereo. Looking to find out why the transmission shifts so early when in "eco" mode. Also want to know if there are any known problems with rear suspension rattles. I had to dealer trade to get Maximum Steel with the options I wanted. When it showed up, it had a rattle that was identical to a rattle that a loaner had. I already saw something about the transmission so I just need to spend a little more time in the garage!