Sim, eles são parte do mesmo universo. Provavelmente. Ou talvez não. Depende realmente de quem você pergunta.
O Dirk Maggs da BBC certamente pensa que eles eram. E ele tem notas originais de Adams para fazer o backup:
“There is definitely Hitchhiker’s/crossover,” explains Dirk Gently adapter-in-chief and director Dirk Maggs. “In this second series there is one particular idea from Douglas’s notes for the third [unfinished] Dirk Gently book which at one point he thought might be a Hitchhiker’s book. It’s a very simple idea that puts one of the Hitchhiker’s characters in the same universe as Dirk Gently in a way that I thought had enormous potential.
In this series we find that the characters in both universes are inhabiting the same world, and I think where we’re going with this is something that actually resolves later on in Hitchhiker’s. It’s turning into a bit of a prequel!”