FWIW I have this:
It's fantastic, but it's also big and heavy unfortunately. I've only taken it to a few track days and nobody's ever said anything, but I never asked either.
Only complaint is that it's big, so I won't put it on the front window, only on the rear deck and even then I get slightly concerned about visibility (I always think there's someone behind me.
But it will hold a full-size camcorder. Cruise Cam does too I suppose, but it's *right* next to your head which sort of freaks me out. All the stuff you can buy specifically for in-car video that I've seen is just crappy-ass 640x480 webcam-quality video.