Now that I finished reading all 14 pages of awesome ideas, I'd like to add another and keep this thread alive. I REALLY didn't want to replace the stock head unit, so I sought out to find the best bluetooth option compatible with the stock setup. Ended up finding this little guy, and man this might be the best $20 you can spend on ANY older vehicle. I can't begin to tell you how well it works. It even pairs faster than my aftermarket Alpine deck in my truck.
Nulaxy Wireless In-Car Bluetooth FM Transmitter Radio Adapter Car Kit W 1.44 Inch Display Supports TF/SD Card and USB Car Charger for All Smartphones Audio Players
https://www.amazon.com/dp/B018E0I01I?ref=yo_pop_ma_swf
Just keep the in-dash volume down to medium or lower and control the volume from the Bluetooth unit or your phone and it's clear audio. Hands-free calls even work well!
Nulaxy Wireless In-Car Bluetooth FM Transmitter Radio Adapter Car Kit W 1.44 Inch Display Supports TF/SD Card and USB Car Charger for All Smartphones Audio Players
https://www.amazon.com/dp/B018E0I01I?ref=yo_pop_ma_swf
Just keep the in-dash volume down to medium or lower and control the volume from the Bluetooth unit or your phone and it's clear audio. Hands-free calls even work well!