For the sake of security, your car is equipped with an Audi chip key, ensuring that the car will not start if someone tries to use a copy of your key. Your Audi remote, also, is specific to your particular car. If you lose either item, they must be replaced by Audi or by a vendor who specializes in reprogramming these items to coordinate with your Audi keyless entry system. A quick online search will reveal the resources available to provide an Audi replacement key, and these same resources can usually program an Audi replacement remote as well.