I just purchased a 2018 Impreza hatch with 5spd transmission and I'm constantly hearing a noise coming from the rear. It seems to happen everytime I lift my foot off the accelerator while cruising. Not so much like a mechanical grind but more of a whirring that kind of pulses in and out. I'd like to say it's somewhat rpm specific, being loudest while decelerating between 2.5-3k rpms, but I haven't driven the car long enough to say. It's just loud enough to hear over the radio when it's turned up to half volume. Anyone experienced something similar?