Chevrolet 2002 Cavalier Owner's Manual page 66

When a new vehicle is delivered, the dealer removes the
key tag from the key and gives it to the first owner. Each
tag has a code on it that tells your dealer or a qualified
locksmith how to make extra keys. Keep the tag in a
safe place. If you lose your key, you'll be able to have a
new one made easily using the tag.
One key is used for the
ignition, the doors and all
other locks.
If you need a new key, contact your Chevrolet dealer
who can obtain the correct key code. See "Roadside
Assistance" in the Index for more information.
NOTICE:
Your vehicle has a number of new features that
can help prevent theft. But you can have a lot of
trouble getting into your vehicle if you ever lock
your key inside. You may even have to damage
your vehicle to get in. So be sure you have an
extra key.
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