Next to tackle was the head unit.
Originally suction cupped to the windshield - now you see it:

And now you don't:

Ok, there it is hiding in the windshield surround

The real give-away view is from head on with a flash (otherwise it is pretty much invisible)

How does this get done?
Start by removing the surround (two torx under the visors and pull of the clips)

then the detector head unit - but the top of the case has to go.

On the passenger side dremel out the clip support and the other 'obstructions' to clear a space for the detector

keep going until you get a good fit

...the passenger side clip eventually had to go...

The top of the unit is covered by a silicone rubber anti-skid sheet from another project to protect the electronics and prevent electrical shorts and bothersome rattles.
replace the surround and visors and the view from the cockpit is pretty clean

another small piece of the silicone rubber is used to obscure the volume control knob that would otherwise be visible through the top's hook opening.