Its part of the black plastic bezel piece that mounts to the dash. I have one I need to replace cuz its missing the rubber, just like you, but I have not figured out if it is replaceable without removing the dash. Once the rubber seperates from the bezel, there is no putting it back on.

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I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k