Put in a Yellowbox last year to adjust for 3.73's.
Good instructions and easy install- service manual had the info for which sensor wire does what.
I did the splices on the speed sensor wiring so not to cut the cars harness.
Figured if I fucked it up it'd just cost me a new sensor.
I put the unit in the little well under the front of the center console under the PW switches. Its not weather-proof so an outside install would need to be protected from the elements somehow.
I have the same issue as above- above about 90 mph my speedo needle will just drop to zero for a second, then jumps back up. May do it 3 times on a straight- may not do it for the next 5 laps.
Seems to be no rhyme or reason to it- and no problem. Just a bit of a distraction.
Had it delivered in a week right from the manufacturer in Australia at half price in exchange for pictures of the connectors for the speed sensor.
They were looking to make a plug adapter so there'd be no cutting on the install.
Not sure if they have it done.
Would be worth asking if you want one.
Can't post the site but GOGGLE is your friend...