After being the highest paid star in Hollywood in the mid-30s for Warner Brothers, Kay Francis was displaced by Bette Davis as queen of the lot. In her last years at the studio she was given B-pictures like this one, and her contract was not renewed. After this picture, her last for Warners, the studio pointedly didn't host the usual wrap party for cast and crew.
This film did well both critically and financially for Warner Brothers' B-Picture unit. In a review, "Film Daily" wrote "Mark Hellinger [Associate Producer, uncredited] can take full credit for an excellently mounted, well cast and carried out production." Most of the other reviews marveled that so much had been done with so little.
Denny's plane that Janet flies in the race is a Cessna C-34 "Airmaster", registration NC15821. Made from 1935 to the beginning of WWII, a total of 228 of all variants were made, 42 being the C-34. According to FAA records, this particular plane is still registered to a private individual in the state of Washington (as of 2016).
At the airport, Janet walks by a rare Arrow model F, registration NC17023, made in 1936. Only 103 were built between 1934 and 1936. It was a low-wing monoplane, powered by a modified Ford V8 automobile engine. Its initial price was only $1,500 ($27,000 in 2016).
The use of several uncredited, but recognizable players in dual roles results in some odd situations: Sidney Bracey is first seen at the Burbank Airport starting point, then later he's in the crowd at Cleveland at the finish line.