The car driven by Walter Williams is a yellow 1948 Packard Victoria 8, the most luxurious and expensive convertible of it's day, and America's leading luxury make for several decades. The Inspector played by Charles Coburn calls it a Packard roadster.
The failure of the original copyright holder to renew the film's copyright resulted in it falling into public domain, meaning that virtually anyone could duplicate and sell a VHS/DVD copy of the film. Therefore, many of the versions of this film available on the market are either severely (and usually badly) edited and/or of extremely poor quality, having been duped from second- or third-generation (or more) copies of the film.
Midway through the film, Walter tells Marsha: "A rolling stone gathers no moss." Later, when Marsha asks Walter if he's returning to hometown, Walter replies: "Wild horses couldn't drag me back there." Nearly 25 years after the release of this film, British group The Rolling Stones had a hit with the song "Wild Horses."