Review the service and recall history. I had more than the normal issues with mine to include a transmission shift valve replacement, a shorted ignition harness, failed rear sensor wiring connector, plus the squeaky brake recall. Been trouble free for over a year, however noticed ECO Start-Stop is not working. Very few posts, but suspect battery, voltage regulator or sensor showing low battery voltage. GLC's have a fairly long option list. I purposely had the dealer find one with no leather, no Command Control/NAV, but Blind Spot and towing hitch. My wife's new 2019 RDX has adaptive cruise control and lane keeping which I've learned to like. IMO Blind Spot is a must. I can get 30 MPG on a long trip. Not sure what actual changes were made between 2016 and 2017, but 2016 had many of the typical first model year issues.