I'm not sure if its been there since new, and I'm just now noticing it more (I bought it this past summer), but my 2009 GT has a faint clicking sound that follows the rpm's coming from the motor when its cold. The sound fades as the car warms up. I don't think its the usual noisy 3 valve sound that they all seem to make. The car has just 3000 miles on it. Its more noticeable with the windows closed than open. Is this common, or should I take it to the dealer to be checked?