I have just bought a new sony head unit and 6 x 9s, and had to customise to plastic Mouldings in the rear of my car to suit my 6 x 9s. I need an idea of what i can put in to stop the vibrating.

if the speakers are vibrating the parcel shelf, you will need to screw them down better, try taking it to a good car audio place, and they can lokk and advise the best option.

you could also try installing some sound deadener on the parcel shelf as well.

Cheers Joel

make some mdf spacers...

it may not be your 6x9s vibrating. what car is it? if its a removable parcel shelf-like a hatch back it could be your actual shelf vibrating on its supports- it depends on how the shelf is supported. i did one in an older civic and it was supported by two pins at the top to pivot the shelf up and i just wrapped some electrical tape around the pins so they were tight. and use some foam tape for the rest of the shelfs supports.