I’ve purchased a fair bit of gear in the last few months for mounting both my video camera and DSLR in the car and I thought I’d take a few minutes and describe the setups I’m using.
First up is the Gripper suction-cup mount from Filmtools (which I bought back in January and didn’t remember posting about). It’s nothing more than a suction cup with a plunger that draws a vacuum, a Bogen 3D head, and some custom hardware to tie the two together. It’s simple and effective and well worth the $90 or so I paid for it. The rubber suction cup itself is quite rugged, and the vacuum pump helps to make a nice firm seal to the surface. The pump plunger has a red line on it, and when that line shows, you know that an appreciable amount of suction has been lost and it’s time to take action. Honestly, when the red line shows, there’s still quite a bit of grip, but when you’ve got more than a thousand dollars worth of sensitive equipment suspended above the ground you probably shouldn’t mess around too much. These pictures were both taken using the Gripper mount:


The straight-ahead shot with the Gripper was taken using this orientation:

Note that the camera’s mounted upside-down to accomplish this. I have kind of a love/hate relationship with that head. It’s more flexible than probably any other head I’ve seen and is an excellent fit for this application, but the three knobs and independent axes of adjustment are a royal pain in the ass, and I’m constantly pinching a finger in there somewhere.
The other mount is a CruiseCam in-car headrest mount. It’s a simple mount that clamps to the two supports that make up most adjustable headrests. The camera gets positioned between the two seats and will typically look straight out the front or rear of the car. I used it for the first time this weekend at an autocross and I think I like the results (although I haven’t even seen the video off the camera yet). The mounting options aren’t as flexible as the Gripper, but it gives you a couple that aren’t possible (or aren’t as “good”), those being the straight-ahead or -behind shots. You can also use it on the rear headrests.
Here’s a rear view of my video camera (and associated wires…) mounted to the CruiseCam:

I’ve only taken a few stills with this mount and it was on a very bumpy road; the results of longer exposures (1/10s) weren’t very good due to the massive jarring of the car. The test videos I’ve taken look pretty good so far, however. This is one quick shot I took with my wide-angle lens and the CruiseCam:

For video, I’m using a Sony DCR–HC96 MiniDV camera, a Sony VMCK100 microphone adapter (the –HC96 doesn’t have a regular mic input), an Audio–Technica ATR–35S lavaliere mic, and the Sony DC adapter for power. The stock battery’s good for about 20 minutes which is pretty damn pathetic in my opinion, especially since the large capacity battery’s over $100. Acquiring this rig is another post (hell, book) in its own right, and I’ll let the results speak for themselves (soon, hopefully!).
For both the CruiseCam and Gripper mounts I’m using a Bogen 3299 Quick Release adapter. It attaches to any support that would normally screw into the bottom of a camera but provides a quick-release feature that’s really handy. Once the camera’s aimed, you can remove it from the mount without having to worry about aiming it again later. It also makes setup and tear-down much easier. I’ve got two or three of these, now, and need at least one more.
I’ve got a small set on Flickr showing the Gripper and CruiseCam mounts in my car to give an idea of how I use them and what’s possible.