Yep, the clios and other Renaults had/have athermic coated windscreens. Its an anti uv coating, but it has the side effect of damping or reducing the transmission of gps signal through it.
The square gap is in the coating to permit transmission of gps for satnav, mobile, and in some European countries such as France and Germany, the signal to/from toll systems such as toll2go or the short range comms systems also used for toll charging.
If you look at various cars, normally easier when the car is coming towards you, you may notice the slight purple or green tint to the windscreen. This is normally the athermic coating.