I have around the same commute time. Lectures in the car don't work for me. Language audio lessons such as Pimsleur were a little better but still require a bit too much concentration. I can however listen to audio books and follow along.
Glad I did a text search before commenting so I could vote you up for Pimsleur: I found the Pimsleur language learning approach great for the car when the commute is mostly on a freeway rather than a road with traffic lights.