Yes to above , look for contact points. noises are some time hard to track down. While riding if I here a reoccuring noise I will stop and tap around to try and recreate and localize. My fender contact rattlle point is between rear fender stays and rack struts. Choose your cure. Cork, leather or rubber are all nice.
I spent way to much time trying to find an unusual noise from disposable water bottles. The other day I had a new noise and pulled over into a parking garage only to realize it was a carabiner on my belt loop with a house key.