Well, it's not quite an audio book, because it's streamed and not a downloadable file, but it is free. I had two long journeys this week and listened to the first two books. http://www.ancientfaith.com/podcasts/series/the_chronicles_of_narnia
I had the flu when Elle was watching the BBC Chronicles of Narnia films from the library. She was about six. I had been up puking all night, and my darling hubby thought he'd do me a favor...and put a DVD in for her on his way out the door to work. "Hey, let's let mom rest this morning if we can." He got her a snack, let the dog sit with her on the couch...was trying to help me out cause he knew I was in bad shape. He'd called my mom to come help, but she wouldn't be arriving for a couple hours due to her own doctor appt. I was laying there, clutching my Kleenex and puke bucket, trying to find the courage to get up to use the bathroom. When Elle is suddenly standing next to the bed...tears GUSHING down her face. "they killed him. Aslan is dead. they killed him." she could barely whisper it through her sobs. She was inconsolable. "Elle, go watch the rest. It'll be ok." "They KILLED him!" "I know, but go watch." "I can't! It's horrible! Why would anyone make such a horrible story?" I hauled myself out of bed..squeezed between the kid and the dog...and watched the rest with her. Looking back it's incredibly funny...but in the moment...LOL Hubby called later, "Hey Hon, how you feeling?" "Aslan is dead. They killed him." I told him grimly. "Oh SH*T! I forgot about that. Sorry!" LOL