Turns out it was not the end of the story. After that was "Mostly Harmless"
Oh, I didn't know there was another book after the two Dirk Gently books. Salmon of Doubt. I am going to have to buy that for my kindle account. I thought I had read everything from him. Yes, including his Dr Who stories. Those were the best written in the entire history of that series, and I will say that stands still. The best thing was that they were played in the TV version by the best Doctor as well.