When I started my event business last January, I found myself spending a lot of time in cars, driving, usually in Los Angeles, usually late for my appointment, usually lost and always in traffic. It was excruciating to just sit and wait for the traffic to move, so I decided to start driving with my camera in the car and as I sat in traffic or moved very slowly along I started shooting. I would stick my camera out the window (always praying I didn't drop it) or press it up against the windshield and just start shooting.
Shooting while driving is a tricky concept. You can't really look through the viewfinder while driving. Sometimes I know what I want, but usually I just shoot hundreds of pictures and when I upload the photos I find images that I never even saw--angles and viewpoints that just seem to magically appear. It is amazing and very exciting.