I was at the junkyard a week or so ago and there was a mini cooper that had the panoramic sunroof. it has a rollup sunshade similar to what our rovers use but the difference i found is that the clip is held in by two phillips head screws. I didnt think to grab it to test till after the fact, mainly because i had recently fixed my shades and didnt have a need for it. since the only option we have now is to bodge something together or replace the entire shade i figured this might be of some interest. I dont have a part number and the only image i could find of the clip is the following attached image with the part of interest circled in red: