I'll bet most folks have already seen this, but I just came across it as I like going through Periscope Film's YouTube stuff. Kinda surprised me, most of their stuff is military documentaries and training films (check 'em out if you ever wanted to see your old Army VD films), but they have a few indy 500 and NASCAR stuff as well. This one popped up and it's amazing. It says "70s" but I'm not sure what year, the silly counter covers it up. But enjoy "Formula Vee presented by Volkswagen of America"
https://www.youtube.com/watch?v=B8f0Ca0-tnM