Weird noises
 

So on my way home from work I decided to do some WOT pulls to let the car get a little exercise with a pull in 2nd gear. I only do this really once a month or so. But this time when I let off the gas around 6k I hear a weird sound every time i let off. I cant really point out where its coming from since I dont hear it though my driver window. But I plan on bringing it to my local dealership in the Am. I was just wondering if this happen to anyone else and if they have taken it the dealership what was the out come?
btw i driver a 2012 Tour sport with 14000 miles.

"weird" sound like what? clunk, rasp, ting, etc...