[Peter Serio]

GM used 2 separate means to isolate the lens and keep it from rattling or creaking when the outside temperature changes.


First are 2 strips of "tar" as shown in the photos above. In behind the bezel you can actually see there are 2 raised ridges molded into the plastic which is the area where those tar strips nest. And second: there are 2 pieces of 1/4" long cut vacuum hose. They attach into the back of the bezel. In-between circle opening #1 and #2 plus openings #2 and #3 there are a pair of un-threaded "posts" molded in. On top of each post it gets thinner and that is where the vacuum hose rests. When the 4 gauge attachment screws are tightened the front side of the lens presses up against both ends of the cut vacuum hose and that puts a very light amount of pressure up against the clear plastic. Mainly that is what keeps the lens from making noise.