This may cause some level of surprise, but it’s a BMW i3 which had its sound system developed by Harmon Kardon.
They updated the audio components for the 2018+ LCI models, and I must say it’s potentially even better than the branded Harmon Kardon premium option. I hadn’t realized that two mid-range speakers could create such an expansive and separated sound system. Then the bass drivers can be adjusted to preference without negatively affecting the frequency response. I was expecting to be incredibly disappointed by the base audio system, so my expectations were dramatically exceeded. I can’t emphasize enough how natural and detailed the default treble tuning is.
My mind is blown that two exceptionally-phased, naturally-tuned speakers may be even better than multiple speakers throughout a vehicle—for front passengers at least.
A vehicle’s cabin has grown to be my preferred place to listen to music, as a good sound system can be like an expertly-crafted speaker system that’s specifically been designed for the environment and acoustics despite road noise. Also the bass boost EQ on a good system should be customizable to preference without becoming muddy.