Visit this site for more information on VW Keys.VW keys are very handy. The vehicle’s key has a chip inside of it called a transponder. It looks like a glass tic-tac. When you put the key into the ignition, the reader coil will energize the transponder in the key. Then the transponder will send a code back to the coil and on to the evaluation unit. If everyone is authorized, the evaluation unit will authorize the vehicle to start. If not, the car will start, or it will not stay running.