So, just got back in after taking a "fresh look" at the area around the racetrack and the railroad. I highly doubt that simply stopping the train adjacent to the entrance is going to happen... For a variety of reasons. There is about a 10' difference in elevation between the road servicing the racetrack and the railroad, with a culvert between them, as well as tons of brush and grass and all the uneven terrain an injury lawyer could ever dream of. Not going to happen there unless they build an ADA-compliant level-boarding platform from nothing in the next two months.
BUT! On the south side of CA37 (basically, 180* from where the picture above was shot from the Googlemobile as it went over the grade crossing) there is a very flat dirt road on what I would presume to be private property running adjacent to the tracks for a good quarter mile. If the train was ran over to this section and stopped, a shuttle system of sorts (trams or charter buses?) could then pick up the passengers and bring them to the raceway with ease. If I were a betting man, I'd wager something like this is the plan. If this thing ends up being a roaring success, maybe an actual station facility could emerge in future years?