My Prius has now stopped dead 2 times while driving at 65 mph. Lucky that no one was tailgating.

The car would not shut off and the axillary battery then died while I was waiting to be towed. The hazard lights went off when the battery died.

The first time the car worked fine after the battery was recharged and no further problems were identified.

6 weeks later it happened again and the car is now at the dealership.

Any similar problems?

Any information I can give to the dealer who seems to be at a loss the explain the problem ?