What are my options for upgrading the sound from the stock system?
Excellent! Lane might have some wiring schematics??? Also, you'll find them in Haynes repair book. Pretty much, put whatever you want in your Saturn. My nephew put a massive system in his 1997 SL, and unbelievably, the stock alternator stood up to it! Schoche makes many of the connectors that you may need, you can buy then anywhere.
