Hi to forum
I too bought some genuine Renualt aerodynamic bars for my Scenic on
but didn't check to see if I had the black strips with the flaps to slide back to fit the bars to the roof.
The bars arrived and I then realised I had a problem. I took off the plastic strips (they just pull off - take care with the front and back finishing caps at each end so as not to break them) which revealed three fixing points (from memory) on each side to clamp the bars to.
I didn't want to drive the car around without the black plastic strips on and so measured carefully where the bar's feet should pass through the strips and with a drill and stanley knife carefully cut out slots at the right position.
I then refitted the strips and clamped the bar's feet through to the roof. I then carefully refitted the end caps.
One didn't fit properly and I had to use double sided tape (with foam between the sticky sides) but it went on and has stayed on (two years now).
You can apparently buy roof strips with the right slide back openings but Renault charge an arm and a leg.
I leave my bars on and check they are clamped tightly regularly so they don't part company. I took them off on one occasion when we travelled gown to the Vendee in France without our roof box attached and wanted to be aerodynamic. The holes I had cut bugged me so I bought some simple carpet tape in black and after cleaning up the plastic strips with turps and left to dry they went on a trip and stayed on until I returned home and put the bars back on.
I will prob sell the Scenic with the bars left on so am not worried about the slots that I cut into the strips.
The bars make no noise whatsoever and I can't really say I get less MPG with them off.
Hope this is of interest.