I got a set of the "standard" Renault Bars brand new in box for £27 +£9p&p a few months ago. No issues with the panoramic sunroof - the mounting points are same whether or not the panoramic roof is there, and the Renult bars do not foul the roof when it is open. The Renault designed bars fit really well and are robust. As theres absolutely no play in them you can confidently load up as required. Only criticism I'd have is the incredible whistling above 60ish - suspect the profiled grooves on the top of the bars are the culprit.
We have a standard (not grand) scenic, but the roof width / bars part number is same for both models - the grand simply gets the additional set of rear mounting points allowing both bars to be "parked" at rear if desired.
If buying on
kep your wits about you and dont bid too high or too early - they seem to appear fairly regularly so if the price goes up wait for the next set.