Strictly speaking, Dirk Gently's Holistic Detective Agency #2 is not an Oz comic. But if you know anything about Dirk, you know how odd things can unexpectedly flit in and out of his life. So it should come as no surprise that, while leading a spontaneous walking tour around San Diego*, Dirk leads them to the famous Hotel Del Coronado and mentions that L. Frank Baum once threw a legendary party in room 3502 for the movie Munchkins. Oh, yeah, not a word of that is true, but L. Frank Baum got a name check! That's pretty cool, isn't it? It's especially cool if you are aware of Frank's connections to the Del.
* (Hey, it can happen, especially if you're Dirk!)