I've never been in the infield in Santa Anita, so I don't know the logistics (it has it's own parking area), but I almost always end up missing the first race there. Finding the right path to the parking lot is a maze (I think they might move the barriers just to play mind games) and there are so many levels of admission it takes awhile to get to you area. I also don't usually stay for the last race, so I'm not complaining about missing races. If the car show doesn't before the first race, I wouldn't worry about timing so much. Unless you have a reservation at Frontrunners or something.