It's not so much the camera but the mount! And as for the camera, lens angle gets real important. I'd suggest getting any camera you want (I'll always recommend sony) as long as it has video/aud "in" capability. Then go to www.chasecam.com. This guy has done the research and offers minicams you can mount anywhere on your car. Too cool.

I have an I/O Port rollbar mount for my Sony PD150a. I will be changing to the chase cam arrangement this year.

Steve