Have been trying to track down an annoying squeak from behind my dash for about a month...the squeak would come when going over a gentle bump. If if was a longish one, you would hear the squeak on "compression" and "rebound". I hunted all over the inside of the car, spraying silicone spray on all the door and targa top gaskets, shift lever, clutch linkage, clutch cable, etc, etc. I was getting frustrated, and found little left it could be.....then I thought, what about the suspension bushings? Sound was coming from what appeared to be right behind the dash, not outside the car...but.....so I jacked up the right front of the car, and sprayed silicone spray on the top upper bushings of both the A-arm and shock mount. Quiet! Fixed. Next oil change, I will spray ALL of them, just for kicks, including the sway bar bushings.