You where spot on the garage said the sunroof needs to come out nothing to do with the screen . Its sorted for Monday £40/- .
£40 is pretty good JTL. I remember fixing exactly this problem on my daughter's Clio a few years back. Took weeks to source the problem, then an Internet trawl to find someone who had fixed said leak, then 4 hours of frustration before finally conquering the thing, followed by an enormous sense of pride

when all was refitted and the interior was dry.
She sold it a month later

Jeremy