Just a cheap magnetic mount I found at autozone.
Took out the clock (because it didnt work anyway) and cut a piece of wood the same size as the clock. Covered the wood with a piece of black plastic and epoxied them together. Drilled a hole through both and then put a bolt through that sticks out the front. Cut the arm of the mount to size and filled it with epoxy and sunk a nut into the epoxy.
Yeah, its dusty but I live and work in the desert and I would have to clean it every day if I wanted it spotless.