1* purchased March 2018 (Acadia denali) since August 2018 in motion when I accelerate it sounds like a loud lawnmower & crackling sound in rear muffler area. Took it Chevy place in glenpool, ok. They couldn't find anything. 2* on 2 occassions, in motion, the car accelerated with a loud noise & as if it were getting power & not moving then jerks & speeds up about 15mph faster & I couldn't stop it. I kept slamming on my breaks, but the break would only go in so far. I was frightened with my 2 young boys in car screaming. It's like riding a horse & it takes off & you can't control it. 3* on about 8 or 9 occassions stationary I get out of my car & it makes a really loud annoying sound like a machine/robot powering down. My kids always say, it's going to blow up 4* the most annoying, for past month...stationary, every single day & time I turn my ignition off. It has loud beeping sound & check rear seat flashing on screen then shift into park flashes. This occurs every single time I turn my car off. Sometimes I have to just let it go on all day because I can't get it stop. I turn car on & off shift back & forth & it still will not go off. Sometimes it does after long periods of time. I don't have time to struggle with getting a car into park every single time I turn my ignition off. I have to beat it forward hard with my hand to the point my wrist is bruised. Now I have to use my foot to kick gear shifter into park. I'm afraid T's going to roll out & or down and hit something, someone or even one of my children. Which would not be good. I've seen several of same complaints. This really needs to be investigated & recalled asap. My elderly mother had to call my brother to another part of town to beat the gear shift into park. This car was brand new & I shouldn't have any of the above mentioned issues. It's frustrating thinking GMC was top of the line & it's not.

- Okmulgee, OK, USA

The contact rented a 2018 GMC Acadia. While the contact's friend was driving 40 mph, the engine revved and the vehicle accelerated on its own. The brakes failed to stop the vehicle. As a result, the vehicle drove through a partition and crashed into a brick wall. The air bags deployed. All four occupants in the vehicle were injured and received medical attention. The contact suffered chest pain, another occupant sustained a cut on the head, and the other two occupants suffered fractures. A police report was filed. The dealer and manufacturer were not contacted. The cause of the failure was not determined. The vehicle was destroyed and towed to a tow lot. The failure mileage was unknown... 'parts of this document have been redacted to protect personally identifiable information pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).'

- Columbia, MD, USA