* Vehicle manuals: The owner's manual for your Cavalier may include a section with radio schematics.
* Online forums: There are a number of online forums dedicated to the Chevrolet Cavalier, and some of these forums may have radio schematics available for download.
* Auto parts stores: Some auto parts stores may have radio schematics available for purchase.
If you are unable to find free radio schematics for your Cavalier, you may be able to purchase them from a dealership or other automotive service center.