Until the car ignition is on, the overlay is off. This is expected.
If it's still empty while driving, the scripts are probably not running. In this case make sure the files are presents:
C:\Program Files (x86)\SimHub\NCalcScripts\SimHUDProjection.ini
C:\Program Files (x86)\SimHub\JavascriptExtensions\SimHUDProjection.js
and restart SImHub.
That worked... thanks!