When Whitney asks Gus and Shawn if they watch USA Network, Gus says not since 2014. Psych (2006) used to air on USA and ended in 2014.
When Shawn and Gus meet the Rental Office Manager, Shawn introduces Gus as Burton Guster Rodriguez, then says "It's always been there." Recently, the actor playing Shawn has switched to using his official last name on credits: James Roday Rodriguez.
At one point Shawn gives Gus the alias Black Jack Arnold. Jack Arnold was the name of the dad on the original The Wonder Years (1988). Gus is played by Dulé Hill, who is playing the dad on the new black version of The Wonder Years (2021). He is the black Jack Arnold. Additionally, Allen Maldonado (Allen Decker) has a reoccurring role in the New Wonder Years as Coach Long.
The pineapple can be found in Curt Smith's music video at 1:33:12.
The Alan Decker tribute at the end of the movie is for a re-recording mixer who worked on Psych (2006) as well Psych: The Movie (2017) and Psych 2: Lassie Come Home (2020).