I listen to a lot of podcasts. That's all I do while in the car. Here is a list of all of the photography podcasts to which I subscribe. Yes, the list is long and yes, I do listen to every episode. Luckily there are many that are not weekly shows! They're all good and they all offer unique content. A few are available in both audio and video versions. Some have a specific point of view, like travel or street photography, and others are more general. If these aren't currently on your list, I suggest you check them out.
My favorite podcatcher is Downcast for iOS. Does everything I need it to and never fails me. As of this writing, it's $2.99 in the App Store.
Street Focus with Valerie Jardin
Mirrorless Minutes with Jamie MacDonald and Mike Boening
Digital Photo Experience with Rick Sammon and Juan Pons
The Candid Frame with Ibarionex Perello
The Digital Story with Derrick Story
Improve Photography with Jim Harmer
Out of Chicago with Chris Smith