How Not to Go Off the Grid

Marissa Battle and two friends marched out of the woods after a strenuous 5-mile hike near Olympic National Park, excited for the rest of their “Twilight” getaway weekend in Forks, Wash., the rural setting for the popular vampire romance saga.

Then they got a jolt: They were locked out of the car. The trio had rented a technology-reliant Hyundai Elantra from Zipcar, Inc., which had given the vehicle the fun name of “Monroe.” The car-sharing service owned by Avis Budget Group Inc., operates rental cars equipped with radio-frequency identification, known as RFID, and Bluetooth technology. “Monroe” is locked and unlocked through an app on a cellphone.