Schneider's use of a CB radio to help search for Julie and Chuck was both novel and timely. While truckers and other drivers had used Citizens Band for years to spread information, its potential was still catching on with the general public.
Chuck's father's mention that his son wouldn't take a woman across state lines (despite Julie announcing their plans to travel) is a reference to the Mann Act, which made it a crime to do so "for immoral purposes" (like cohabitating).