What is the Smart Key System in an Audi A4?

I'm looking to purchase an Audi A4 and I've heard about the Smart Key System. What exactly does this feature do and how does it work?

The Smart Key System is one of the standout features of the Audi A4. It allows you to lock, unlock, and start your car without ever having to take the key out of your pocket or bag. Simply approach the car with the key on you and the car will automatically unlock. When you enter the car, the key will be detected and you can start the engine with the push of a button.

The Smart Key System is a convenient and time-saving feature in the Audi A4. It uses a sensor in the door handle to detect when you are approaching the car and automatically unlocks the door for you. Once inside, the key is recognized and you can start the car without inserting it into the ignition. It's a small but impressive feature that adds to the luxury and convenience of the A4.