Well my original thought was that with the proliferation of MP3 players that have voice recording capability, that would be the way to go. That said, I had not thought much past that.
So, if video is the only way you can do it, then that is fine by me. I can strip the video and just save the audio track anyway. So have at it. The important thing is that every clip is taken from the same area behind the car as per my first post and that all the relevant information is collects also per my first post. With that, people should be able to see where they are and compare it to what they are listening to.