I bought my car in February of 2016, the noise started in March, go figure right?
It sounds like a soda can full of pennies and it's fairly loud. Somewhere behind the engine. It only happens on acceleration or while cruising at speed on the highway. It also only happens under load, put it on a lift and it doesn't happen. I just got back from 2 different mechanics and a transmission shop, neither of them seemed to be able to figure it out without getting into costly tests. The only leads I have is it could be a heat shield that they couldn't see or possibly the flex-plate on the flywheel.
I will try to get a video of it later IF I can because it only happens while driving it.
I've browsed the forums and looked at other peoples "noise videos" but I don't see anyone else with the similar problem. Any information or leads would be much appreciated. Thanks in advance.
2010 Fit Base Model Automatic 109k

 

I had a similar issue on my jeep, it was a small piece of the guts of the cat converter that had blown back in to the muffler, it sounded like it was up front but it was a trick f how th sound transferred though the chassis.. So Check the WHOLE exhaust, I used a rubber mallet and started at the back tapping on it every few inches and finally got the noise.

 

I have actually replaced the muffler since the noise started. I might take off the rest of the exhaust and check it out.