My credit card wedged under the tower brace is holding up very well after a week. I only hear the clunk when I really hit a harsh bump, and its between 45 and 65 degrees outside and the car is cold. Before the credit card that would mean it would sound like driving down the street in a model T ford or vintage farm tractor. Constant clunking/rattle on every few revolutions of the wheels.
There is a photo of my credit card shim in the other thread of zillon's