I don't think $100 is too much. It would save me a lot of time making something myself. I think it would be very useful for those with multiple vehicles. And when someone else is driving your car you probably don't want them messing with your EQ settings. So with a box that plugged in and powered the amp and passed through the AUX inputs would be very useful.

Reg #2845: Mark 1 #00173, Mark 2 #119