The on star feature malfunctioned and was un-usable for the last 800 miles of a trip. Had static, would not turn off and was unable to comunicate with the On Star advisor. The next morning the battery was dead. Jump started and ran. The On Star has worked fine ever since but the car has had to be jump started 10 times in the past 18 months and 2 GM dealer service departments have not been able to find the problem, one dealer kept the car for 2 weeks and it started every time. It is on its 3rd battery in 18 months.