A fixed daily slot really can turn into another obligation (and then the backlog becomes guilt again), whereas a lightweight “I’m in curiosity mode” toggle matches how attention actually works. The driving “radio” use case also suggests the output should be low-friction: short, self-contained, and not demanding follow-up right now.

If I were to design around your constraints, it would look like:

* a manual toggle for “curiosity mode”

* a queue that plays 1–3 small “snack” insights (not full summaries)

* and a single “save this to revisit” action that you can do in 1 second, so you don’t lose it while driving

One question: when you hear something interesting in that mode, what’s the most natural next step for you later—open the original link/video, add it to an “active project/topic”, or capture a single note like “try X / look up Y”? (More context on the direction I’m validating is in my HN profile/bio if you want to compare.)