Re. presets for different volume levels, how about (and this might be getting a bit silly, but possible nevertheless)....

- Attach a speed sensor to the serial port to give speed dependent volume.

- Attach a GPS receiver to the serial port, also giving speed dependent volume but this time it still works if you're on a trailer. :)

My Carin 440 does this, and it's *very* useful in a high road and wind noise car like the MR2 with the top off.

Taking this train of thought a little further, could the IR sensor be used to measure the ambient light somehow or is it too narrowband to notice daylight? If you can measure light levels even roughly then you could have daylight and darkness visual settings to avoid having to turn off the fancy but bright visuals at night when they're too distracting.

Cheers,

Mark.