I had EXCELLENT results from my rear-facing camera, which was just a hacked, $20 Canon Powershot A530: www.ronman.org/pics/lemons_fall/in-car
This hacked camera also can record video at decent resolution and, more importantly, will fill a memory card instead of hitting a 1GB limit like most do. You could conceivably use a couple of these things mounted front and back and swap memory cards and batteries when you change drivers/fuel/blow a head gasket.
We had Judge Murilee's RageCam mounted on the front bumper and got pretty good video from it, too: http://www.youtube.com/watch?v=Dq6gf4NqV5g
Back in April at Lemons South Spring, I mounted my Samsung HD camera to the rollcage crossmember basically where the dash would be; unfortunately our Lincoln doesn't have a windshield, so the camera's outer lens paid a heavy price. That footage was natively 16:9 but my old software didn't process it right so it's squished, but here's how it looks:
http://www.youtube.com/watch?v=bdO-oPIPKsQ
Now, recommendation-wise, if you're gonna mount it behind the windshield (which you totally should if you value it at all) then you want something with as much manual control as possible. A flash-memory camera is also the way to go, for ease of editing as well as durability. As you can see in the spring video, my camera's lens is not very wide, so for Lemons use it's really not the greatest thing in the world. That's the biggest problem you're gonna run into, honestly. There are screw-on wide angle adapters you can get, however, and they run about $100.
I'm not sure what your budget is, but an HD flash camera is going to run you a minimum of $500, plus $20-30 for memory cards. I get about 2 hours of video on an 8GB card at 1080p.
What kind of budget are you looking at?
Official photographer/Team Police Brutality|Speedycop & the Gang
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