Even if you own a Tesla, you should still carry your car keys at all times.

Tesla owner, Las Vegas investor and entrepreneur Ryan Negri learned that the hard way as he got stranded with his Tesla six miles from home near Red Rock Canyon, Nevada. Negri used the Tesla mobile app to start the car at home, and didn't bring his keys; but when he had to stop and restart the car to adjust a dog seat, there was no cell service, so the start-with-phone method was useless.

"Need to restart the car now, but, with no cell service, my phone can't connect to the car to unlock it. Even with cell service, the car would also need cell service to receive the signal to unlock," Negri described the event on Instagram.

To start the car, Negri's wife Amy had to walk 2 miles to get cell service, then call a friend to take her home and pick up car keys.

I knew the day would come where we would get stranded with the Tesla. We had "no service".



Long story, ask @RyanNegri. — Amy M Negri (@AmyMNegri) January 14, 2017

Negri told Mashable via a message that he was aware that the mobile app won't start the car without cell signal, but he simply forgot about the poor cell signal in the vicinity.

"Forgot when you get out of the drivers seat, you have to re-initiate the sequence to unlock keyless driving. After I adjusted the dogs bed, I got back in and I had access to the cars display panel and all options besides to drive! I could even play music from my phone because my phone was synced via Bluetooth," he said.

And even though everything ended well, it was still a pretty dangerous situation. "We got out of the car and waited on the side, because it was a thin 2 lane road and it just didn't feel safe. Something worse could have happened," Negri told us.

While taking your car keys when you go for a drive seems like quite an obvious precaution measure, the technology that makes our lives easier can sometimes make us forget the simplest of things. Sure, it's nice to be able to unlock and start your Tesla with a phone, but car keys are still a very valid addition to your pocket necessities.

While acknowledging that not taking the keys was definitely his fault, Negri suggested that Tesla should add a password-protected way to start the car from the mobile app even when there's no signal.

@Lee_Ars @isaac32767 @internetofshit just the manufacturers.



Should be both a password solution if I already have access to the panel. — Ryan J Negri (@RyanNegri) January 14, 2017

Perhaps Tesla engineers take notice, and the app becomes more friendly to forgetful Tesla owners.