Um, sorry about that. I was not paying attention to this thread... It took an email message to gently prod me in this direction...
(Edit: <groan> The coffee is kicking in, and I just realized what I typed... Sorry about that...)
Yes, there are at least a few versions floating around on empegs out there.
For the Hitchhiker books, I have all of the books (well, the ones that were completed) as downloadable audiobooks from Audible, converted to MP3. I also have a live version of HHGTTG excepts that Douglas Adams performed before a crowd somewhere. And also a variation from a record (vinyl) production that was made and released in the US.
For both of the Dirk Gently's, there are full versions from Audible converted to MP3 along with a version (sadly it is an "abridged" version) that was released on audio book CD, ripped to MP3.
Why? Is someone looking to provide me free off-site archive and data storage services for these files???