rattle from sterio in trunk

[vaspen]

what has anyone done to get rig of the rattle from the trunk where the spare tire goes
car is a 00 230 komp sport

I have the trunk cut up to have my exhaust the way it is, but it vibrated the same way before I did this

is the metal there like 2 peace's or something ?
I know its right in the center of the spare tire part because when I push on it it stops but I don't know what I can do to keep a constant pressure on it

[wichipong]

do you hear the rattle from inside or outside?

[vaspen]

outside the inside I have so sound matted I cant hear a siren right beside me lol
but the trunk it only dose it when the lid is closed whats the point of having a good bump when all anyone els hears is BZZZZZZ BZZZZZZZZBZZZZZZZZZBZBZBZBZ

[wichipong]

maybe the license plate is the one rattling?

[vaspen]

Nah I have a small peace of cardboard behind it I can literally push on the center of the trunk from under car and it stops vibrating