I wouldn't mind some auditory feedback on engine performance, it can be very useful. I definitely don't want it to be simulated noise that's meant to approximate some fictional engine. Making it specific to what it is for and embedding more useful audio clues within it would be good (along with the ability to easily disable).

As someone who's owned a few older cars, the sound is one of the most useful early diagnostic tools. It tells you immediately how the engine is running. Often you can tell the difference between a cold engine and a hot engine running. Losing this entirely isn't necessarily a good thing, but neither is faking it, which is the worst of both worlds, no useful information conveyed (beyond possibly RPMs, depending on implementation) but noise nonetheless.