We must be shopping at different stores. My experience with cassette adapters (and I tried quite a few different ones, back in the day) was always muddy, bad au

We must be shopping at different stores. My experience with cassette adapters (and I tried quite a few different ones, back in the day) was always muddy, bad audio quality. FM transmitters (good ones anyways) never had that problem. As for Bluetooth as a standard: what, exactly, is not a standard about the audio portion of it? You can take any device that supports Bluetooth audio output and connect it to an audio playback device (speaker, head unit, whatever) and it will just... work. Super old speaker to brand new phone? Plays audio fine. Super old phone to brand new head unit? Same thing. This isn't some 'big techy is out of touch with reality' thing. We just have alternatives that are perfectly practical for edge cases where you absolutely need that aux jack, and the vast majority of consumers have moved on years ago.