One other feature that will be very welcome is fast burst mode. You really can't pan with something moving as fast a race car and get anything with single shots. My camera does 10 frames/second but I'd think you want at least 7. For something as fast moving as auto racing, even experienced shooters will toss a high percentage of their shots, hoping for a few that are sharp.
More importantly, are you really proposing to buy a new camera you have never used and take it to a high energy event expecting to get usable shots? You really need to have some experience with whatever you will be shooting and practice things like panning technique to have any hope. The camera cannot do the job for you, the user is key. Learn the system and practice the techniques and you might bring something back worth having.