I found a quiet stretch of road today to have a bit of fun - naughty I know but its good to allow the car to stretch its legs when its safe 8-). Anyway, in second and third gears I took it close to 7000 RPM without this screeching sound I mentioned. I then eased off a bit and eased into 4th and 5th gears, then accelerated a bit more in 5th. When I was at approxiametely 140KPH it started screeching quite a bit behind the dash. I eased off and within slowing down 10 KPH or less it was quiet again - no screeching at all.