NHTSA Complaint #11681821 — 2025 CHEVROLET TRAVERSE

This vehicle had 19500miles on it when we picked it up at the airport rental agency. It was 2WD model. We used it for 2200 miles on a family vacation and 95% of this was interstate highways. Smooth road surfaces. The travel conditions were sunny hot, dry. There were 6 passengers and a decent amount of luggage. Rear cargo area still had foot or more of space though so it was not stuffed like for a beach trip. At one point after getting on the highway from on ramp, there was a horrible sound. It got louder and louder quickly and caused us to panic. My husband looked in all the mirrors. He said it sounded like a Peterbilt semi was barreling down on our ass. But there was none in the mirrors. He quickly let off the gas pedal during this and the sound went away. As we sped up again though, it did the same thing and this time even louder. Starting around 72mph. Something was resonating in the body or powertrain of the car and it seemed like it was about to come apart! We did a check quickly, all of the windows were completely up, the AC was on. The radio was off. He slowed back down, the sound went away. But for 3rd time of trying to reach 75mph, the whomping sound came back and was so intense, it was debilitating and he almost could not hear me talking. We didn't know what to do. He braked immediately to pull off to the side. On a busy highway. After we stopped he got out to look at the tires but we did not a have tire pressure gage. They seemed perfectly normal. He looked under car, in wheel wells, opened the hood with the engine running, shook the car from side to side. Nothing was found loose or hanging down. After this, we could hear the same type of sound at 54mph, 60mph, and between 72-77mph , it all came down to what RPM and gear the transmission was in. This seems like a total design flaw in the chassis or power train. We told the rental agency that no one should be using or buying this car until the issue was fixed.