On my open race car I use a "bullet" camera mounted to the roll bar. I feed the signal into a recording device with analog inputs. In the past, I've used Canon or Sony Mini DV camcorders.
This weekend I will be trying out a DVR that records directly to memory stick. This is a pretty slick looking little device. I will post my results.
A good supplier for remote cameras/DVRs etc is
Security Camera, Video Surveillance System, CCTV Camera Security System, Wireless Video Security