There is another TM thread previously on this topic - https://www.talkmorgan.com/ubbthrea...ance-autoroute-toll-tag-on-cx#Post799877

Personally I did have a few problems getting it to register through the heated element of the CX windscreen but there is a 2 inch section down each side without the element and we attached it there (inside the glass just above where the passenger side windscreen wiper rests), which seems to work fine. see picture in the other thread.

Good luck!