Try popping in an aftermarket radio/stereo - you can get a nice Pioneer with a USB fast-charge port and Bluetooth/etc for ~$100-150.

FWIW Subaru kinda just has crappy digital components. Corresponding touch screen console from recent year Toyotas are pretty good, especially with CarPlay / Android Auto.

In my recent Subaru Impreza, CarPlay works just fine, however when I start the engine and put it in reverse, it will mostly ignore the volume control until you finish backing up and then a few second after you shift into drive/forward, it will then process the volume up/down messages it received in the meantime. It's like it dedicates all processing to booting up the screen and then in displaying the rear-view/backup camera. Also, it defaults to playing the radio (even if you had it OFF before, I think), so if you had the volume up for a quiet podcast or something it will blast the radio which is quite annoying, especially if you're in the middle of a phone call or something. I want a physical potentiometer which directly controls the amplifier to the speakers, like in any normal old radio. (This is also one of the exhibits in my mental list of reasons that people should write all the software they run on their devices. Or at least be able to.)

I don't think it's bogged down processing. It is explicitly muting the audio as part of the reversing protocol to avoid distractions, and possibly to let you hear other sounds such as from a parking assistance system.

> It is explicitly muting the audio as part of the reversing protocol to avoid distractions

No. It is NOT letting me turn down (or up) the radio. Meanwhile the radio plays loudly.

Sorry for misunderstanding and for not noticing your message before! That certainly sounds like a poor UX! I have only driven other brands, and have only seen an opposite effect. Some systems seem to have a multiplicative factor, so you CAN turn it up and then be blasted with very loud music after switching to a forward gear and having this mute effect released.