They come with a sat-nav type mount, big sucker on the windscreen type thing that bolts onto the top of the unit. It takes an SD card (that you have to buy separately). I think 16gb or 32gb is the max. At 720x480 it records around 100mb/minute, but it keeps cycling so it just records over the oldest stuff if you keep it running. Also when you plug it into lighter socket it powers on/off and starts and stops recording with the ignition.
How long does it record for before re-looping back to the beginning ?