Be aware that copyright most certainly does apply to all these manuals, and will do so until 70 years from the end of the year in which they were issued. I understand that BMW are the owners of the copyright, and have a history of taking people to court. However, it is possible that it is not BMW that owns them, but rest assured, someone does!
There was an effort by the Libervative (or maybe Consiberal?) government to do something about copyright on "orphaned works", but I don't think that the law has yet been changed. It does need to be, for reasons such as this, where people that NEED information can't get it because the original manual is out of print, and get sued by the copyright owner when, as a last resort, they are forced to make an illegal copy.
I am not admitting to owning any dodgy material, for obvious reasons, but suffice it to say that I have had similar problems with the manual for my daily driver, a Ford S-Max.
So, if you see a real, genuine workshop manual at an affordable price, grab it, and look after it well. Making copies of a few pages to take into the garage, to allow the original to be kept clean, is fully legal in the UK. I suspect that making one scanned copy of the whole manual for BACKUP purposes is also legal, within UK and EU law, however selling manuals on CD is a SERIOUS CRIMINAL OFFENCE in the UK, and can result in a few years holiday in one of Her Majesty's less salubrious establishments. (Ebay always removes such stuff and bans the seller, once someone notifies them.) Possessing a copy, or giving one away free to a friend, is only an offence under civil copyright law in the UK, for which you can expect damages of about 4 times the value of the illegally copied material (say £100) plus the, probably much larger court costs, so you could be out of pocket by over £1000 quite easily.
If you live in the US take great care. Some poor woman was done for several millions by a stupidly incompetent judge and jury for a couple of illegal music downloads valued at maybe $25 total. That is done under civil law, and if you get into such a case it is almost certain that you will be bankrupted by the legal costs.