Trunk rattle





Last week, I developed something loose underneath the trunk, about right in the middle. The actual splice is strong and solid, so it's something else right there that is rattling.
I took it to a dealer near me--not Selman yet--and they couldn't find the rattle, but offered to drill a few holes and inject some foam. Whatever I do is going to be covered by insurance, but I want to do the right thing.
Question I have is...I know this is almost impossible to answer because it's pretty hard to say one person's rattle is like another's........but has anyone else had a problem like this? I can duplicate it also if I bang just above the deepest part of the trunk. I guess i'm asking what could be underneath that area of the trunk and visually-inaccessible from under the car.
Thanks for any help you may be able to provide.


