I can get autosave working again, but it is at the expense of losing your profile, and starting again.
They are stored locally in in a folder called remote (which must go to the cloud). The folder called local has a gamesave folder in it, but there are no files in either folder, probably because it's demo.
During this attempt to fix the problem, I have disabled the cloud for the game, as I don't want it to overwrite what I am doing.
Looking at the file names, this appears to be EXACTLY the same bug that was in F1 2011. I think there were 2 methods of recovering your profile in F1 2011, I have tried one, but that cost me my profile, so I am about to try the other one. I am definitely not impressed.
EDIT: Both of the old methods used in F1 2011 failed to recover the profile. The only good thing is that I got a chance to create a new profile, and start again. This time I have switched off autosave and gone to manual. Neither auto or manual worked prior to creation of the new profile