Since Auto Save has a design flaw (it disregards the last manual save when counting the specified save duration) and automatically saves the project without the permission of the user (who often doesn't want the time-consuming save to take place while concentrating on something), I suggest that a toast notification that says "Saved?" or something appear (in a different color than the usual green, and probably in the center of the screen) which kindly reminds the user to hit Ctrl+S to save the project. I recently disabled Auto Save (as Sonar became very stable) and decided to constantly hit Ctrl+S but was too focused on editing for a while and then the program crashed, taking away all the edits I did before then. 
 
The feature should be optional, of course.

I'd much rather see auto-save improved somewhat (like fixing the issue you mentioned with disregarding the last  manual save). Overall, it works quite well and saved me quite a few times this year.
 
However, auto-save could be more "intelligent" or more configurable because it's totally different work it needs to save when you compare e.g. MIDI editing vs. remote controlled tracking sessions (the later might require quick saves after each recording, while this would interfere too much with MIDI editing) ...
 
I'm sure the collective wisdom of the user base could compile some great suggestions as regards "intelligent" auto-save          

I agree. Probably the true intention of this request is to have the Bakers start developing the intelligent auto-save feature.
You know, developers don't usually like implementing what their users suggested as is.