One scene has three men talking by a parked pick-up truck. In some shots, the truck is a Studebaker with a rounded roof and fenders. In other shots, it's an International Harvester with a squared-off roof and fenders.
When Cherokee Jack is flying Griffin, Cook, and Landis down to Cuba, rain is spattering flat against the right side window of the airplane and running straight down. If the plane had actually been in flight - or even running - the drops would be blown almost horizontally across the window.