WARNING:
Leaving children in a vehicle with the ignition key
is dangerous for many reasons, children or others
could be badly injured or even killed. They could
operate the power windows or other controls or
even make the vehicle move. The windows will
function with the keys in the ignition and children
could be seriously injured or killed if caught in the
path of a closing window. Do not leave the keys in
a vehicle with children.

The key can be used for the ignition and all locks.
The key has a bar-coded key tag that the dealer/retailer or qualified locksmith can use to make new keys. Store this information in a safe place, not in your vehicle.
Notice: If you ever lock your keys in the vehicle, you may have to damage the vehicle to get in.
Be sure you have spare keys.
If you are locked out of your vehicle, contact Roadside Assistance. See Roadside Assistance Program.
Remote Keyless Entry (RKE) SystemChevrolet Cobalt Owners Manual. Wheel Replacement
Replace any wheel that is bent, cracked, or badly
rusted or corroded. If wheel nuts keep coming loose,
the wheel, wheel bolts, and wheel nuts should be
replaced. If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer/retailer if any of ...