Driving? I'd be surprised if it weren't a factor. With that said, I'd like to think the age(/race) of decision-makers/general historical inertia are greater causes of the disparity (for popular media anyway). In the long-run, women voting with their feet/wallet is what will "correct" the current situation (IMO).
The dearth of intelligent female voices in popular media is depressing (is there anything sexier than an ambitious, intelligent woman?). While I think there's some value in shame activism, an issue like this is better addressed with the provision of useful information to those who do or might care. What are the causes of and potential solutions to the underrepresentation of women? Are there good movies/shows directed by or starring women I should be aware of? What else can I do to help more female voices be heard?