As an alternative you could use a pass through speed sensor mounted at the cable drive on the trans and dakota digital converter to convert the 8000ppm sensor to the 2000ppm required for our cars. I did that some time ago.
I have been looking at that. The biggest complaint from the reviews are that the GPS needs to see the sky. Guess that means having that black box sitting on top of the dash.
I have one of those stupid dealer installed astro roofs that I wont ever try to open due to not wanting to wear it out and source new parts for it. Maybe it can be hidden up there?!