I was looking at doing that and came up with the idea to remove one of the back rest bolts and replace it with a longer bolt. I was going to run a nut up to the same height on the bolt as the head on the factory one and then epoxy the nut and a piece of 5/16" stainless tubing to the bolt. I am not sure about how much stress the connection point underneath could take so I have put it on hold for now.