If it has a keyhole, it will let you use a non-transponder key to open a door. The problem though, is that more and more cars are using laser cut and sidewinder cut keys, which your typical key-cutting place can not duplicate. So even if they want a non-transponder key for the doors, it can be difficult and expensive. Sidewinder keys generally look like this:



With that in mind, the average owner doesn't usually get any spares made beyond the 1-3 they get when they buy the car.

Then, to make things more difficult, quite a few cars make using a key somewhat tricky. They might hide the actual key inside the remote fob itself. Then, to use that key, you have to locate the proper key hole, which can be surprisingly difficult on some cars.

The corvette is a great example of this. It uses a completely electronic based locking and unlocking system. While it does have emergency back-ups in place, most owners have no idea how to use them to get in or out of the car. It has actually led to a few calls to police from panic stricken owners who think they're trapped inside their car when the battery dies.

Here's a video of how the back-up lock systems work on a late model corvette. It's good to know, because you're probably going to see a lot of similar systems used in future vehicles: