I have a GPS Speedo and just plugged the speedo hole on the transmission. Mine is F5 but this is the company that makes them:
https://www.speedhut.com/gauges/?catid=f19 These speedos work really well and acquire quickly.
The plug I used for the speedo hole on the T5:
https://fortesparts.com/product/fort...ter-hole-plug/
Had a leak from the speedo hole before I installed the plug.