Mercedes-Benz S580 4Matic Incident

All prior narratives have been removed due to character limit. Please see reports 855-1341-(1 through 3) to see prior updates. 01/[XXX]/22 Update to 855-1341-3:The customer submitted a Vehicle Owner's Questionnaire ("VOQ") to NHTSA, complaint ID 1758659. An update is being provided based on new and differing information provided in the VOQ mainly with regards to the circumstances leading up to the alleged collision event. "The contact owns a 2021 Mercedes-Benz S580. The contact stated while driving at 60 MPH, the contact pressed a button on the steering wheel to engage the cruise control function on the vehicle. The contact stated when driving past a mileage sign stating 40 MPH, the vehicle suddenly reduce in speed to 40 MPH, while the contact was on the highway in the fast lane. The contact was able to move the vehicle over to the side of the road waited a few minutes took off the cruise control function and reapplied it back on and continued to drive the vehicle again. After a few minutes when the contact was exiting off the highway and the contact drove past a sign that said 60 MPH when suddenly the vehicle automatically accelerated on its own which caused the contact to rear-end a parked vehicle in front of them. The air bags did not deploy or the S.O.S. signal did not turn on. The contact was injured where they broke two bones in the right foot, left knee injury, and whiplash on their neck due to the seat belt. There was medical treatment at the scene. A police report was filed. The vehicle was towed to a local dealer where the vehicle was inspected but could not diagnose the caused the failure. The vehicle was not repaired. The manufacturer was made of the failure. The failure mileage was approximately 976."