A Tesla Model S owner got stranded in Red Rock Canyon near Las Vegas after intentionally leaving his car’s key fob at home, all because he wanted to try out Tesla’s new control app. Turns out, the smartphone feature that allows drivers to remotely monitor and control their Teslas without their keys only works as far as the smartphone has a signal. Ryan Negri found that out the hard way when he and his wife went for a drive without the key fob to test out the feature. Chalk this one up to an experiment gone bad.