Originally recorded December 6, 2019.

If you have an older vehicle that uses a key with a transponder chip built in (usually has a rubber or plastic part you turn), eventually, the teeth on that key can wear out as the car ages. When it's time for a replacement key, you can't just get a key cut, you need to get a special transponder key that is programmed to your car.

If you have two keys for the car, chances are, only one of them is worn, and the other one is fine. Take that key to a locksmith and have a copy of it made to just a plain metal key. Now when you try the metal key, the engine won't start.

So what you can do is make a "key sandwich", with the head of the old transponder key that is worn out held to the new metal key, and it'll work just fine. You can experiment with different ways of attaching it. You can take a hacksaw or Dremel tool and cut the worn teeth part of the old transponder key off. Won't look pretty, but it will work, and save you hundreds of dollars!