In 2017, my 2015 C300 2.0L frequently failed to start the engine. And the frequency of failure increases to an unacceptable level. Since the car was under extended warranty, the dealership took around 2 months to fix the problem. The error code I got from a repair shop says the car cannot communicate to the engine. The first time I went to the dealership, the car did not fail to start so it cannot be fixed. Next time, I took a video of the problem and showed it to the dealership. They kept the car for more than a month to find out it's an electrical problem. One of the signal wire between the main computer and the engine system is broken.