For the psych and soc section you could also use: dr. Bloom's psych lectures from 2007 yale opencourseware (easy listening and he is pretty funny I think) or KDpsych mcat audios on youtube.
For the MCAT science, aside from audio osmosis, you can also just throw youtube videos on in the car and just listen, I found this extremely helpful, or you could even do so for Chad's videos which many people say are really great.