The E30 Bentley manual goes to 1990. The E36 Manual starts from 1992. So unfortunately we have the one car that need both manuals.
The E36 manual for us is specifically useful for M42 info and can be found easily, just look for the links above. It is a computer version, I don't remember if a paper version for the E36 was sold but it's definitely not sought after as a book cannot compete with a 1000+ page pdf file. The E30 Bentley manual which deals with the rest of the car does not seem to have a computer version being from the 80s and we haven't been able to find a scan for download.