It is a good idea to make a mechanical key, one that does not have a transmitter.  This is the type of key that will aid you if, and when, you are locked out of your vehicle, for whatever reason. 

These are also the type of keys that cannot start your car’s ignition, but they are handy if you have locked yourself out of your car, and this has happened to all of us at one point or another. 

They furthermore also have the same cut as your car key and will help the auto locksmith make a duplicate in the case of you being locked out of your car.