i just recently bought a 08 g37s, i brought it to the local dealer and had the exhaust changed due to the rattling noise caused by a broken weld containing to the baffle on the inside. im not sure if i heard this noise before but i now hear a clinging, ticking type coming from the bottom of the car when im stopped say at a fast food drive through where it reflects off a wall or something. it also happens everytime i have been driving and turn the car off, i have heard this sometimes on other cars after they were shut off, is this a normal sound?

 

its the heat shield

 

just make sure, on my 08 it turned out to be loose material in cat ratteling