I checked the Crutchfield site, the 2002 Cavalier like my 2010 Cobalt uses the radio and speakers for the turn signal/warning chimes. An adapter is required for an aftermarket sterero. Crutchfield sells the adapter for ~$65 (1/2 list price) with the purchase of a new stereo. Spend a little time on the Crutchfield site to educate yourself on the options available.
Ed B.