I know I read it on the navplus forum (well it has a new name now), but I tried doing a search and nothing came up. There were some posts about people adding them on.

does anyone have these for sale?

that website is annoying to use.

They're not really from the RNS-E so you have to do some alterations on the large knob in order to get it to fit. You also have to remove the front panel from the RNS-E in order to install it.