When I slow down to stop the RPM's rev up and down, I guess the motor is gearing down, but it seems the vehicle gets confused on what it wants to do, stop or keep going. I have taken this vehicle in to two different service departments. But they can not duplicate the problem. I told them that the vehicle doesn't do it every time I stop. There are times that the stop is smooth, other than the gearing down on this new vehicle I am not usto. The vehicle also acts up when the car is just coasting at a slow speed, when my foot is not on the brake or accelerator, it gets confused whether to go or stop, almost like it wants to die. Also when I idle the vehicle rpms' will drop real low and the vehicle seems as if it shakes to rev back up to the correct idle. The biggest complaint is when I brake or at a real slow speed, just coasting. I drop off and pick my kids up at school so there are a lot of stops and starts. I have had the technicians (Gabriel Jordan Chevrolet, Henderson, TX) to keep my car for several days which was an inconvenience , in hopes they would find the problem, but they could not duplicate it, said they checked it out the transmission and no signs of malfunction. Also one day I was coming home from church traveling a road I travel once a week, the message Grade Brake On came on, I was going down a hill but not a steep one at all, I did slow down due to a car in front of me, The next Sunday I traveled the same road and about the same area I slowed down again and applied my brake but no message about grade brake this time. I also told the service department, they checked and it didn't show the message came on big surprise. I got my car back and told them there was a problem with this vehicle . I have spoke to the service department where I bought the car, and the first time I took it over there on Aug 30th (I bought the car on July 5th) I told them something was wrong with the car, the tech drove it and told me that there was a throttle issue and he had several to come in and complain about it, he has contacted GM regarding this issue. He believed a recalibration needed to be done, told them they made a note of it, and I left. I went back a second time for the same issue, they can't duplicate it. bla bla bla. The service dept installed a recording device, I returned it when I recorded the vehicle acting up, but it didn't show anything. I was later contacted by this service department (peters Chevrolet, Longview, TX) stating they sent it in the GM, and they should be doing a reprogram or recall on this problem, that there were several having the same issues. Nothing but a big pain in the ass, I have also had the car to accelerate on its on, like a lunge forward and back when I was at a slow speed taking off from the pick up line at school. It seems to me the vehicle doesn't know what to do. Today it was a real notice when I came up to a red light, when I applied the brake it seemed it geared down to low and raised back up then done it again to low and back up and leveled out that time, its like you hit your brakes for a second then release it. I'm tired of it, frustrated..