 Bought this low mileage GLK 4Matic and have driven for a month including 900 mile trip. Car is very quiet and accelerates well. Only problem so far was a dead battery in a proximity key. Navigation and audio system are a challenge to understand basic issues like setting radio presets without breaking out the manual.Update 7/17/2018:  We've now owned the car for 1.5 years and have not spent any money on corrective maintenance or had any warranty work done.  The tires are showing some wear so they will need to be replaced in the not-too-distant future.  And over-time we've learned how the electronics work (or at least as much as we want to learn).  Other than having one or two times when I wished the cargo area was bigger and having to use premium (91+) gas and the known high cost of Mercedes scheduled maintenance, I have no complaints and am happy we purchased this car.