The seven is for the racing footage; I'd have to give the film as a whole something lower; this looks like a standard "programmer" from the period. I've seen "TCR" several times, and this time decided to watch it to try to determine where the racing footage was shot and what kind of cars these are.
I have to (somewhat educatedly) guess that we're looking at the old Jeffrey's Ranch Speedway in Burbank in the first racing sequence. It was pretty close to the Warner back lot, and (according to racing historian Harold Osmer) in operation from '31 to '35.
The stands are covered, and there are a lot of large trees close by, as well as equestrian facilities, all three items definitely not the case at Legion Ascot or Huntington Beach. I've been told that Culver City's half mile of that period did not have any equestrian facilities, either, which deals with all the tracks in the region in '31 and '32.
The cars in these shots are largely Ford-Model-A-block / any-odd-freer-breathing-head, rear-drive, backyard/filling-station bombs on Ford rails rather than anything from Harry Miller's shop in nearby Vernon, though there might be an early Miller 200, 220 or 255 (the basis of the famed Leo-Goosen-designed, "Offy" 255/270 built by Offenhauser & Brisko and, later, Meyer & Drake).
This is doubtful, however, as those engines and complete (usually two- or three-year-old) Miller chassis rarely ran anywhere but Legion Ascot in the LA area at that time.
The second (nighttime) sequence is at Legion Ascot, and its 20,000 seats look to be pretty full, which, even when they weren't shooting a feature film, were pretty full even in the nadir of the Great Depression. Veteran dirt track fans will note that Ascot's oiled surface runs pretty much dust-free compared to the old horse track in Burbank.
The third group of action sequences shot at the Brickyard feature top-of-the-line Miller and Deusey rails, as well as several of the very best drivers of the period including Fred Frame and Billy Arnold, both Indy winners (1930 and 1932, respectively; Lou Schneider won the '31 race in the Bowes Seal Fast Special seen momentarily here). Careful listeners will hear the unmistakable snarl of the early "Offy" fours in the background.
Sadly, the sound era was just getting underway as the legendary Miller 91s and the incredible board tracks they ran on were phased out in '29. Open-wheel racing in the '30s was -good-, but OW racing in the previous decade (at tracks like Beverly Hills and Culver City) was as big -- and spectacular, and fast -- then as NASCAR is now on mile ovals.
The Indy scenes feature the (more nearly "stock car") two-seaters and "poor man's" engines that were mandated at the time to reduce costs and break the high-tech/high-buck, Miller stranglehold of the late '20s. There were Deusies, Fords and even Studebakers running the big tracks in those days, but Harry Miller's cars and engines continued to dominate.
