toll tags

Hello, please can anyone advise where to position a Liberté toll tag on the windscreen of our E-class estate? It's 2017 registration and has no speckled area around the rear screen mirror to indicate where to position the tag. Thanks

Hello - first post so please be patient with me! I drive a 2013 (facelift model) E220 SE CDI Estate. I am heading over to France in August and I want to purchase a Sanef Tag to allow me to use the priority lanes at toll booths. The instructions on their website say to place the tag in the...