According to Geekwire, it's a little-known security feature for the BMW ReachNow cars seen around downtown Seattle.
Geekwire said one of the customers was stranded on a ferry for four hours this weekend because of the problem.
ReachNow said it believes the issue was related to a security feature built into the cars that is triggered when the car is moving, but the engine is off and the doors are closed.
It may have been the motion from the waves during the ferry ride that made it seem as if the car was being stolen.
GeekWire said there have been "multiple recent incidents" with the vehicles.
The company said it’s reaching out to the customers affected this weekend and is in touch with the Washington Department of Transportation to determine how to resolve the issue.
BMW debuted its ReachNow service in Seattle last year. There are currently 700 vehicles available in the area and the company is looking to expand in the Seattle region.
The rideshare program allows members to unlock and drive ReachNow cars through an app on their phones.
Members are charged by the minute. Once done with the car, drivers park and lock the vehicle.
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