Sanef Liber-T Toll Tag fixing query - solid black screen panel?

[magicsurfbus]

The area inside the mottled boundary on my windscreen, in front of the rear view mirror, is solid black.

The fact that there is a mottled area suggests I have an athermic screen (2017 Fiat Ducato 2.3), so will the tag still work if I fix it inside the black bit? Does it need an optical line of sight with the scanner on the toll barrier? Sanef's instructions are a little vague on this.

Ta in advance for any advice and pointers, especially from those who've made it work, or not.

Broken Link Removed

 

[gerry mcg]

I had our fix mine here on our 2017 Euro 6 ducato under order to get it to work. just back last week.
below black area. (we don't have an athermic (reflective) windscreen.
it did not work further up and to the right
you can easily see if you have an athermic windscreen by looking at it from the outside. it looks reflective - you see Renault cars with them quite often. we have a small mottled area too, so that is not an indicator

.