The first thing to appear onscreen is a little blurb about the Yugo car company using the town of Verplanck as a test area for their new model years ago. Every vehicle in town that is not a truck is a Yugo, except the police cruisers, which are Plymouth Horizons.
The "Fetzer valve", when Lucinda the mechanic is giving the Sheriff her findings about Mona's car, she says the "Fetzer valve" had been punctured. A "Fetzer valve" is a fictional part of an engine, introduced in the movie Fletch (1985).
Every character's automobile has personalized plates.
The character name, Wyatt Rash, was intentionally chosen by writer, Peter Steinfeld, to reflect the underlying premise of the movie -- said fast enough, it sounds like ... yup, White Trash!