Tink think making me crazy

[MntGoat205]

I have a 2014 ram 1500 single cab 4x4. Just 39,000 miles. When I'm driving on anything that isn't basically the definition of "smooth" there is a tink tink sound. I only hear it if the back window is open. Best way I can describe the sound is if you let keys on your keychain hang loose and then gently tap them with your finger. I've heard it ant anll different speeds from 10mph to 100mph. Possibly something in the gap between the cab and the bed?

Anyone have this problem?

 

[tron67j]

Heat shield near the muffler possibly. Could be loose.