Has anyone else encountered this problem? I'll be taking it in to Subaru since it's obviously under warranty.

From the outside it sounds like a ringing noise, but in the engine bay it sounds like a hissing, maybe a vacuum leak. It only occurs at 800 RPM or less. I'm pretty sure it's some sort of leak, not so sure what's causing it. I guess I'll find out after I take it in for service.

On a lighter note, my car is finally broken in. Now I get to have some fun and see if it's faster than the 240.