[SirBrass]

I don't really see a need for volume control there, b/c of the readily available physical volume knob on the HU itself. Physical buttons for the touch screen are definitely helpful, but redundancy for the volume knob is adding unnecessary complexity for this DIY. With another HU, I'd say it's a good idea (like one with just volume up and down buttons like my last HU, the Pioneer App Radio 2), but for the stock Subaru HU....? Nah. If it's easily doable, then sure, but if it'd add some headaches I'd say leave it.

But that multi-function switch/knob idea is brilliant! I like! If you get the circuitry and programming devised and set up for easy DIY, I'd love to try it.