Just picked up my Volt from Los Angeles and drove it back up north.
Unfortunately, about half way through the trip the service engine light came on. I spoke with On-Star and they mentioned that it the engine had detected a problem with the secondary emissions control system, and that it was safe to drive on, but should be taken in for service within a week.
Has anyone had this issue or anything similar? I'll have to find a local dealer to take it in to on Monday.
Other than that (and the strangely decreased MPG after it came on - dropped to ~34MPG from ~40MPG) the car really is a pleasure to drive. I'll need to learn to watch my speed in sport mode - the car is sneaky fast.