I always use my tag by (me or Ann) holding it up as we approach the barrier. Keep the bar code side pointing forwards so you just see the black side. This ensures that you do not accidentally leave it attached to the clip on your windscreen when you stop for a coffee or parking.
I don't even leave it attached to the screen on the tin top it only requires a hammer to get it!
When off the motorway it gets securely stored in The Librands foot locker (another brilliant invention!).
And back to the Péage tage - if any of you are travelling on your own in a RHD car it is almost essential.
Quentin