This has been asked many times.
To my knowledge, there is not one. The car was a limited production run, there are two engines, (similar but enough extras on the 3.8 to require a substantial rewrite of any manual), and seeing as it cost close to £50k, the "average" owner from new probably wasn`t the type to get their hands dirty.
The nearest is the Bentley BMW 5 Series Service Manual 1989-1995, an american tome available from
www.amazon.co.uk , oddly enough amazon.com are not listing it at the moment.
Paperback - 672 pages (1 January, 1997)
Brooklands Books; ISBN: 0837603196
Covers the E34 series. Everything is there except the engine and some of the trick suspension on the later cars.
I`ve not investigated the ETK/TIS disks for M5 engine diagnostic and workshop details, I`ll leave that to others.
If anyone here works for or has access to BMW and any official microfilm or printed documentation, surely now the cars are approaching 7-12 years old, BMW wouldn`t mind too much a leak into the owners public domain? Pretty please ??
Ivan.