I noticed yesterday that once the engine is warmed up, I can hear a vacuum sound when the clutch engages the next gear. I hear this on switching to any gear. I also heard it today, driving it to work. I plan on putting in storage this weekend.

Is this normal?

Only recent maintenance was an oil change 2 weeks ago.

I don't recall this on my MY 05, but I am still trying to learn my MY07.