Use bubblewrap. It's thick but fits, keeps the door more quiet, when driving and sounds more solid when you shut it,.. and warmer on your left leg in the winter.
haha bubble wrap. this threads pretty funny to hear what everyone used. i used an old shower curtain
...BTW your Bieber avatar is awesome.-Malone
enough boost is when you have 3 dimple marks in the hood from the valve cover nuts..