I've used LimePod in Seattle, you can't lock your car without cell service, which guarantees you'll only be able to unlock your car if you had service prior. Th

I've used LimePod in Seattle, you can't lock your car without cell service, which guarantees you'll only be able to unlock your car if you had service prior. The key is permanently attached to the ignition, so you could leave your car unlocked and start it later if you were in the wilderness. I wouldn't recommend taking any of these free-floating cars outside of the city because of problems like this, though.