clunking sound from muffler/exhaust

[Ilikemazda]

Hi, I just got my new 2010 M-3 GT 6MT today and i notice theres a clunking sound from muffler/exhaust pipe, I think its from the left side exhaust (left side exhaust viewing from the rear of car). This clunking noise usually occur when my car is idle and is pretty noticeable from time to time. I did not notice this clunking when i give it a little gas or when my car is moving, seem like it only occur when idle or when Im starting from a dead stop. The noise sound like metal rubbing (it actually sound very similar to a lose catalytic converters cover). Is this normal for a new M-3 and the noise will go away after a while or should i bring back to dealer immediately to fix the problem?

[Donutz]

I say it doesn't matter what it is, your car is still relatively new and under warranty, so take it to the dealer. Are you certain the sound is coming from the exhaust?

[Ilikemazda]

cant be 100% sure but it is most likely the exhaust, anyways i will bring to dealer to check

[mazda lover]

does it happen after you turn the car off? if so its the exhaust expanding from the heat, usually happens with a new car, noticed it on mine when new after a while very rarely hear it

[Ilikemazda]

I got the car checked out today and fixed the problem, so far its nice and quiet after service. Dealer advised the heat shield needed adjustment.