Even better, offer tourist books on CD that explain the highlights of the area one is driving around.

I think this could be done in conjuction with audible.com. The car rental company would offer you the full selection of audible books and you could pick one out and they would burn the cd at the counter (preferably before you arrive). That way they would have a gigantic inventory. They way I've proposed it suggests buying the book, but I a rental option could also exist--you could pay 45 to rent (in which case you have to return the cd) or $8 to buy.

Nice idea. Why not extend it to airlines as well? Rent a audio book before getting on the flight and return it after getting off or mail it back. A similar service exists at a a few airports for DVDs. If airlines provided a similar service, it would allow them to make more money and create loyal customers.

Gas stations could join the bandwagon too. Pump gas at your regular station and also rent a CD you want. I for sure wouldn't always look for the cheapest gas with this :)

Anyways, there is a country restaurant chain (the name skips me!) in NC and SC which rents audio books. The CD can be returned to any other branch of the restaurant. Sure way to generate repeat business.

XM radio in the cars seems more practical.

http://www.xmradio.com/programming/full_channel_listing.jsp?sort=number

I would rather have this for an extra fee.

Cracker Barrel is probably the chain you're thinking of (they offer tape (and CD?) rentals, and have franchises nationwide.) But the idea of having them at car rentals is super convenient.

Are you listening, Amtrak? Hello?