Whenever I idle my new S2000, and also for a short time after I shut it off, I can hear a loud "click" of what sounds like cooling or expanding metal under the car. It happens once every 15-30 seconds. I'm guessing it's just an exhaust shield reacting to the heat but was wondering if anyone else has heard this.

 

i get the same thing, probably the cat converter cooling down-

 

same thing
i didn't worry too much about it
i thought something's cooling down ...