Quoted:
Try your local library.

I have accounts at the LA libraries and have access to probably thousands of audio books.  Of course I am not interested in all of them but there are enough to satisfy my through through my commute in the 2nd worst traffic in the world.  

I downloaded the Overdrive App on my Iphone which is required to access the books.  I can download 15 at a time (which is too many) and you can save popular books on a wait list.