Hello everyone. I am now officially a CTS owner having picked my up '06 3.6 6spd with 18" performance package just after Christmas. I love the car but one small annoyance I have is that there seems to be an engine "droning noise" at about 2500rpm. I can't tell if it is exhaust or induction, but I was wondering if this is common and also if it is limited to manual transmission cars. Any feedback would be appreciated.