Good afternoon. Our rental car we picked up from the Denver International Airport on [XXX] had numerous incidents of emergent braking at highway and non highway speeds which were reported to Sixt ( car rental) and documented on the dates in which they occurred, [XXX] (7-8 occurrences ) and [XXX] (3 occurrences-2 after a car wash). On the day in which the first occurrences happened, the car rental company representative from Sixt, 3way connected me with a mechanic from Annex who advised washing the vehicle to ensure the sensors were clean. I did proceed to wash the vehicle on 1.25.25. This same company, Annex Automotive, then evaluated the vehicle on 1.29.25 after emergency breaking occurrences continued of which [XXX] was the worst. On [XXX] there were no vehicles in front of or behind us nor to the sides of us and the roads were completely clear. It was also dark out. Attached you will find evaluation with validation there is a mechanical concern with the vehicle. On [XXX] the extremely unsafe occurrence of emergent braking occurred with skidding tires and the doors locking and unlocking at the same time occurred. This vehicle was completely unsafe to drive. I, as well as my passengers/family, are very lucky the road conditions were moderate on [XXX] and clear on [XXX], or these emergency Breaking issues could have caused a serious accident. There were a total of five of us in the vehicle when all of these occurred. I am from Minnesota and have a Yukon XL so I am comfortable with this vehicle This was the scariest vehicle experience I have ever encountered. The company did tow the vehicle on 1.29.25. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)