Is this normal - there is a rhythmic groaning noise from the rear of the car when I turn sharply at low speeds, e.g. into or out of a driveway.

I'm presuming that this is the limited-slip rear differential.

Except: I'm either more attuned to it or it's getting a bit louder. I did have the fluid changed at the regulation mileage.

Not noticeable under any other circumstances, although possibly just muffled by other car noises at anything other than walking speed.

2012 RS V6 manual-tranny. About 40,000 miles.

Thank you.

Charles