I just thought it would be helpfully to make a DIY for how to remove the rear deck rattle (Si Coupe)
Needed tools:
1x scissors
1x long off-pist or similar
1x a piece of foam
First just pull the cover off, carefully.
Then fill every hole with the foam and push the foam firmly in the direction of the rear window (using a long off-pist or a pliers like shown in the first picture)
Then put the cover back and its done.
Subwoofer bass sounds so much more better!!!
PS: I hope my American is good and you understand everything!
Have fun!