My 04 S60R has a strange noise. I dont know if it means the transmission is no good or on the way out. All first four gears are fine. Sounds like a normal engine accelerating and driving. Then when you get to high way speeds and shift to fifth or sixth gear you hear a hissing/whirring noise coming from behind the steering wheel. I shall take a youtube video to show you guys soon. Sixth gear is more noticeable and louder than fifth. It only happens when i have my foot on the gas to maintain highway speed or accelerate. What could it be? It comes from behind the dash. Will check again if the noise is deeper in towards the engine or indeed behind the dash.