Adding a few visual "in" jokes to your layout is an idea as old as layouts themselves, but it can still be fun. Herewith a few of mine: one or two are just jokes, some are literary, show-biz, or musical references, a couple are left-handed homages, and one is a comment on a now-retired local vet who was known for his criminal bedside manner with other people's pets.
Hank Hill has a job on my layout.The original Bowswer Locomotive Works was located in my town (Redlands, CA) and was actually smaller than this. This one's a "threefur": Larry Niven has written many tales of the Draco Tavern, the Perris Hotel features advertising from Roger Miller's "King of The Road" lyrics, and the blue Jeep belonged to Hayduke in Edward Abbey's "The Monkey Wrench Gang". A not-so-subtle comment on graffiti. A scene from "Robocop". I still have to model the van that's crashed into the toxic waste tank. Yes, in real life the vet's office *is* right next door to El Burrito. The proximity is a local joke. One that I missed thinking of but a buddy of mine didn't: the scene from Steven Spielberg's "Duel", where the big black semi rig is trying to shove the car ahead of it onto the railroad tracks. (No photo)