THere is a plastic key that needs the other part as well. The plastic only opens the doors in case you're locked out. I put the plastic part in my wallet - and the piece it needs to start the car in the glove compartment. I don't know if this only comes with comfort access (probably not) but it's a very convenient way to always have your spare. Of course if you're a lady with a purse who doesn't carry a wallet - then I guess you'd need one of those magnets to hide under the car.