Mine are missing, and no auto parts store nearby has them!

 

Beck/arnley makes some 084-2045, but double check that number. Amazon has them. Guess you've got squealing?

 

Shims are usually sold as a set with the pads. AutoZone brake pads come with a single shim, not like factory spec which calls for two, but doubtless intended to replace the double factory shims.

You could just buy a set of pads, use just the shims, and keep the pads around until next brake job.

Don't forget to get anti-squeal brake lube at the same time.