This is a one cool hack if you are going to film anything from the car. Over at CameraHacker.com, it has a quick how-to on making a Car Camera Mount yourself:
Ever since I have had my car on the racetrack, I have had wanted to construct a camera and camcorder mount for my car. The camera mount would allow me to mount a video camera or a still camera so that I can capture my driving experience for later analysis or for art. At the driving events, any loose objects must be removed from the car. Therefore cameras must be rigidly mounted to the car itself. My car happens to be a performance sedan with a rear deck. The rear deck has three brackets for mounting child safety seat. If I mount the camera to one of these mount bracket locations, I would not have to do any permanent modifications to my vehicle…
Building a Car Camera Mount – [CameraHacker]