Not a bad price. Too bad it can't tap into the magnetic head reader in there for power. Set it and forget it.
Yea, I have a car with a cassette deck.

omg I could use this with my old ghetto blaster!

David, I don't see why it couldn't get power from the deck turning the imaginary tape spool. Just have it be a little generator with a capacitor.

@ Harvey I thought that was how they should have powered it as well.

Thinking about it a while, I agree with the other comments, why are you not powering this internally. Can't be that difficult.

I've been wanting something like this for a long time. I currently have one of the "wired" versions and will most likely purchase one of these.
The only reason I can think of to not incorporate the "auto-power" system is that electricity generation creates significant drag. Most of the tape decks I've seen internally are belt driven so I imagine you'll probably just cause the belt to slip and possibly break over time.

@ Harvey, that's brilliant. You could draw a bit of power from that spool. If you couldn't get enough, you could extend the time between recharging. Avoid that "drag" and maybe it would be a couple hours more. Bluetooth is fairly efficient as I understand it. My belt in my tape deck has been running for, well, 14 years now, no issues as yet. Knock on wood.

You could power them internally but you'd probably add 50% to the price. The cost to develop a mini generator and mass produce the parts for a single device with limited sales does not make economic sense.

Just get one of the cassette shaped MP3 players with a memory card slot.

Was Just talking about making one of these last week. How OldsCool