One problem related to horn assembly has been reported for the 2008 GMC Acadia. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 GMC Acadia based on all problems reported for the 2008 Acadia.
My 2008 Acadia transmission failed as I exited a highway (70 mph) and was going up the exit ramp. It began bucking like a horse. Once I pulled over and parked, I could not go in reverse. The car had to be towed and a new transmission had to be put in it after only 56k miles. Also have had the sunroof / moon roof trays overflow because the drainage tubes are not large enough to drain all the water from the trays. The dealership stated it was a poor design and nothing could be done to replace it. Now water has entered my vehicle causing the electrical box to become wet causing the horn to blow randomly and the car to continue running after turning it off and removing the key.