Here are some pictures of my friend's 5-series. I just picked up a flash that will trigger off camera and used my friend's umbrella. My friends and I experimented with different positions on the flash, and trying different shutter speeds. I also broadened my horizons by tightening up the aperture. I normally shoot between 2.8 and 4 with my 50mm, but tried out a bulb shot with f16. I never shoot with that, but now realize there are times when it can be very useful in car photography.
With flash, f2.8, forget the shutter speed:
No flash, f2.8, forget the shutter speed:
No flash, f2.8, longer shutter than previous shots:
No flash, f16, 1 min 30 sec exposure: