Just got a brand new 2010 Wrx last month. It has 1,700 miles on it now. After driving for 5 minutes tonight, I parked my car for half minute and planed to leave. When I shifted into 1st gear and release the clutch slowly, I heard a big noise came out from the car and it's like grinding. The noise disappeared after ran for about 15 seconds. This happened several times. It seems this will only happen at low speed(also backward) and won't last for more than half minute. Does any have the same problem with me? or does anyone know what causes that problem?