I got a datatoys.com XM-DVR Pro MPEG2 DVR and 2-camera kit for my car last year and will never go with another company. The recorder is housed in a tiny (think cd wallet sized) but rugged anodized aluminum enclosure with two slots for CF cards in the side. It comes with mounting flanges so you can bolt permanently into your car like I did, under the dash.
Runs on simple 12Vdc supply and uses all shielded, waterproof cabling. My 580tvl bullet cameras have absolutely incredible picture and are submersible and shock-proof.
If you do any video recording at all in "harsh" environments, low light areas, or tight spaces, it would be a wise idea to check out datatoys.com and see what the best in the market has to offer!