The next day took a few a more. This time without the camera mount. Both of them provided for some interesting effects I think.
The camera mount in my car is a simple project involving an old tripod, drill, and some U-bolts. Perform some basic measurements around your head rest supports (assumes yours are removable). Then drill and call it done more or less. Cheap and effective. I thought for video it would be shakey, but most video camera have built-in stabilizers.