My 2005 Pontiac Grand Prix gxp would often lose speed in curves, climbing hills, or at high rates of speed. I took it to a GM dealer and was diagnosed with transmission problems. I was quoted one price for transmission, labor, and radiator replacements, but ended up paying over $4000. Gwatney in North little rock, ar has a horrible service staff. They were not willing to work out a deal even after informing them I was quoted a different price. They threatened to charge me additional storage fees if I didn't pick up my car. I eventually paid, but I wrote in dispute of price on the receipt. Here I am 9 months later with the same problem! go figure.

- North Little Rock, AR, USA

On 1/23/12, while backing out of a parking space on a level lot, my 2005 Pontiac Grand Prix lunged forward. I immediately hit the brake. The car was in reverse not drive! I attempted to back out again and the same thing happened! the second time it lunged forward so quickly I was afraid the car would not stop, even with the brake fully applied. This second lunging incident damaged/cracked the air dam, as it was now wedged against the concrete parking space divider. At the same moment, the dashboard flashed/lit up like a christmas tree....and the engine stalled. I put the car in park and turned the ignition off..then got out to inspect the damage. Upon re-entering the car, it would not start! it finally restarted on the third attempt and I was finally able to back out of the parking space.

- Spartanburg, SC, USA

The contact owns a 2005 Pontiac Grand Prix. When the window defogger is activated and the windshield wipers are engaged, the vehicle shuts down. While driving 70 mph, the vehicle stalls and loses power. The mechanic stated that the O-ring was missing, which causes the vehicle to lose power due to lack of heat. The mechanic was unable to duplicate the failure. When the contact took her vehicle to the dealer, it was still under warranty. However, when she picked up her vehicle from the dealer, she noticed that 100 miles had been added, which put the vehicle out of warranty. The failure persists. The current mileage is 37,000 and failure mileage was 35,000.

- Cranberry, NJ, USA

2005 Pontiac Grand Prix GT sedan VIN #[xxx] purchased 12/16/2004. Intermittently vehicle stalls/ loss of power in the engine. While driving the vehicle it will suddenly just loses power. You continue to press the accelerator pedal and then the engine will suddenly take back off at a great speed. This has happened while driving normally without trying to accelerate and also while trying to accelerate. The car has lost power while trying to merge in traffic. The car has lost power while trying to cross highways. The car has lost power while just driving down the road. GMC has performed the following repairs without fixing the problem. 12/30/2004 [xxx]-module, powertrain control-engine reprogramming. 01/24/2005 [xxx]-solenoid, pressure control-replaced. 02/04/2005 [xxx]-module, PCM/vcm-replaced. 02/14/2005 [xxx]-pedal, accelerator-replaced. Dealership purchased from capital Buick-Pontiac-GMC 225-293-3500. Dealership has advised that they do not know what is wrong with the car. We have been told that we have to go direct to Pontiac with the problem. Have been in contact with Pontiac since 02/15/05. Pontiac advised that they were going to research the problem and see if any other grand pri was reporting like problems. So far the only advice from Pontiac is they want us to come in and take another Grand Prix off the lot and see if we can get this car to duplicate the same problem. This did not impress me at all. So after waiting for 2-1/2 months for Pontiac to do something to fix the problem, I have decided to report this to NHTSA. Information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6)

- Baton Rouge, LA, USA