Honda Trunk Top Box Vibration

I installed a honda top box in addition to my honda side bags last summer and headed out on a 7 day trip. It seems to be mounted solid but going down the road it vibrates or bounces on every little bump continuously. I don't notice it or see it in the mirrors but if I can reach back and feel it. When I looked into this more it seems like the whole back end of the bike is springy. I am worried about fatigue causing something to break or loosing the trunk suddenly some day.

Does anyone else notice this with their trunk?

I also get a pretty good head shake with the trunk on even unloaded. The saddle bags don't contribute. I think the head shake is due to a light front end but one thought was that the vibration of the trunk is inducing the head shake.

 

Hm....... on the vibration, not sure. I do know the Honda directions for the trunk well kind of leave a LOT to be desired. I had something not quite right but I forget what but noticed it wasn't mounting right before heading out.