And in the garage...
My new (and very cheap) car stereo is controllable with a smartphone app. You're thinking "yeah yeah, so it plays music and takes phone calls, well duh", actually it does other stuff too: I can set up the speaker balance and EQ and other fancy audio stuff in the app, which is a much nicer interface than fiddling with buttons on a car stereo front panel. I am pleasantly surprised by how much functionality there is for such a cheap stereo.