The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving at 50 MPH and attempting to decelerate, the front end of the vehicle began to drift to the right while the rear drifted to the left. The vehicle returned to normal functionality, but the failure became a regular occurrence. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the rear subframe. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was 136,000.