For my 2016 car I followed the instructions provided by Truckin-on in the discussion cited above in this forum. I couldn't find a separate plug with the grey and black wire but located it in the main plug as discussed by Truckin-on. I used a doorbell for the momentary switch and it worked perfectly. I have done the procedure a couple of times, first to get the speedometer dialed in with the factory tires and agains when I replaced the factory tires with Duros. Once you find the correct wire it's a piece of cake.
