It's all but been decided..
Since there doesn't seem to be any usable pc controlled am/fm tuner cards besides the Cadet which is no good since it only has win95 drivers and is ISA, I've decided that I will mount a small digital am/fm walkman in my ash tray.
Since I'm building a double din box i won't need the LEDs and power buttons that I had formerly mounted in my ash tray.
I'll run a light out cable up to my double din player and into the input jack.
To control weather it is "on" or not I will have a button that will activate/deactivate the mute on the input line. or maybe just a on/off switch that will cut or present the signal to the input.
This seems like the best, most invisible solution I can think of.