For one, the Connection Key uses Bluetooth to communicate wirelessly with the Mechanic Advisor app on your iPhone or Android smartphone. That means that instead of only hauling out the device when you want to troubleshoot a particular issue, you can leave it plugged in all the time. For another, the Mechanic Advisor app takes a holistic approach to car health, alerting you to problems as they occur and even providing reminders to change your car's oil, replace worn tires, or get other scheduled service when it's time to do so. It also taps in to a community of mechanics so you can use the app's Ask a Mechanic feature to answer questions about your own particular situation. And the app itself is on the user friendly side, presenting information in a clear and easy-to-read manner that also lets you know whether this is a critical issue, or one you can safely wait to fix.