Startup Idea: Smartphone-Based Vehicle Key Management System

Startup idea to create a smartphone application that communicates with a device in your car via Bluetooth. This device will be connected to the vehicle's main computer allowing you to unlock your car in case you left your keys inside.

As someone who has left their keys locked in my car and in my apartment many times, I think there is some opportunity for a simple piece of software to help with this problem, especially in vehicles. I could see it being something like this:

You have an application on your phone that connects via Bluetooth to a device that is inside your car, connected to something like a USB port, which connects to the car's main computer or brains.

When you leave your keys in the car, you would go to the app and essentially tell the car to unlock the door. I know some newer and fancy cars have this already, but what if you don't have a 2017-2018 mercedes benz or BMW?

What if it is something you could purchase, connect, link to your smartphone and know that you will never have to call a locksmith to come unlock your car ever again?