What a great film of a wonderful track. I went there several times in the early 60's. It was the era of the USRRC Cobras, Lolas, Chaparrals and McLarens. I recall seeing Mark Donahue winning a local SCCA race in a very fast but slow looking MGB.
Those sand dunes made this track wonderful for spectators. Lots of high spots where you could see into the cars and watch the drivers working. They worked very hard over the many turns and hills on this circuit. The sand kept the cars from getting too far from the racing surface but it would catch wheels and flip cars easily. I recall seeing Sam Posey flip a McLaren that way, fortunately he was OK. The pits were also very accessible.
The parking lot was a treat as well. So many Ferraris, Porsches, Healeys, antiques, you name it. Definitely a go-to destination for car nuts, too bad it is history now. Fortunately, a few films like this are still out there. Thanks for posting it.