Local dealer came to collect SWMBO motability car for a service. I mentioned the non-working electric sunscreen (it's a Citroen Grand Picasso).
Just been delivered, with a note "sunscreen working OK", which it is. However, they added "no fault found" ... had to check with SWMBO that it definitely *hasn't* worked since last August.
Conclusion ? They did *something* (if only touch the fusebox) before they checked it.