Fast Fast Fast Shutter speed....when I go to F1 races, I noticed a huge difference when I moved from a D810 to D5. 10+ FPS or burst at minimum. Also, the ability to shoot at 1/1250 or faster shutter is critical, so having good ISO behavior is important to. Look for a camera with low to no noise at ISO 1000-2000 levels. Trust me on this....I've taken thousands of shots of car race 'scenes' and I've learned the hard way as to what works and what doesnt.