When Nancy says to her father, "I'll bet you $23.80..." -23.80 refers to the amount of the weekly paycheck amount given to WPA workers during the Depression. It became an amount often used when jokingly betting someone to emphasize a large amount.
The car Nancy and Ted drive is a 1937 Ford V8 Deluxe convertible coupe (model 78). An example of this car in excellent condition in 2021 could be worth $50,000 or more.
Adapted from the "Nancy Drew" novel, "The Password to Larkspur Lane," first published in 1933. The original author of the novel was Walter Karig (using the Stratemayer Syndicate house pseudonym, "Carolyn Keene"). In the "Nancy Drew" books, Nancy's boyfriend is named Ned Nickerson. For the 1938-39 movie series, his name was changed to Ted Nickerson (played by Frankie Thomas).
First of four "Nancy Drew" films released by Warner Bros. from 1938 to 1939. All starred Bonita Granville as Nancy, John Litel as her father, and Frankie Thomas as Nancy's boyfriend Ted.
Ted's ham radio call sign of "W8YZR" was issued in real life as a special "vanity" call sign by the FCC in 2008 until it was canceled in 2014. At the time of this film in 1938 that call sign was not assigned.