[oxygenjoe]

Cassette to aux in adapter? Like $10. Cd to aux in? Doesn't exist, gotta replace the head unit.

CDs were a step in the wrong direction

[RodgerTheGreat]

Agreed. The period between the ubiquity of 3.5" floppies and cheap USB drives was very uncomfortable for similar reasons. CD-RWs sucked.

[Tepix]

If you had a MP3 capable CD-disc change with say 6 CDs in your car, you had 60 CDs at your disposal. Usually that's way more than the number of tapes had in their cars. And the quality was a lot better than tapes.

Plus if you're into audiobooks you could get away with 64kbit mono MP3 which doubles the capacity.