I distinctly remember developing one when I was around 8. I wanted it then, but it hasn’t shut up since

deleted by creator

I had the same setup going on for a few years myself. The dongle recently bit the dust and I’ve been too lazy to replace it but my car’s bt connection is nowhere near as reliable as that $17 dinky device from amazon. Like 50% of the time my car will throw an error claiming my phone isn’t capable of Bluetooth audio while playing a song from it

(but really really I just want a headphone jack on my phone again)

Depending on your personal circumstances you might not need a rack. I always just take the front wheel off (quick release) and shove my bike in the back seat