I opened the lid on the rear Seat cubby Box the other day and the hinge just fell apart. The plastic section attached to the lid had crumbled - as brittle as wafer biscuits!

I have Googled the matter and have discovered that's a known problem with my model year (2019) due to poor quality product according to topix procedure 78.10.07.

Has anyone else had a similar problem and what was the response from their dealer?

I have the same. Never got it fixed. I have asked the garage and sent them the TopIX. I am waiting to hear. SDV8 AB MY 2020
MINI Cooper S Cabrio
Kit: Jaguar XK140 (in progress - the website is link to build)

Photo here

Click image to enlarge

Looks very similar to mine - bits of crumbled hinge all over the place - I knew it wasn't broken by force and wondered if it was due to the incredibly hot summer last year until I found this TOPIx report using Google

Click image to enlarge

https://store.landrover.com/parts/index/pa...and-rover/

I think I found the part numbers. So the part is GBP 541. The lid and hinge are one piece. SDV8 AB MY 2020
MINI Cooper S Cabrio
Kit: Jaguar XK140 (in progress - the website is link to build)

Thanks for that link - all options show none in stock - no surprises there!
Interesting chat with dealer service dept - they have seen this problem before but said no chance of JLR paying to put it right.
However, I do have the Land Rover extended warranty and I spoke to them and they said they certainly would pay the costs of repair if I submit the claim to them - the TOPix report was all they needed to agree the claim - absolutely incredible!!

Ok, the garage is ordering me the part. They wanted €350 to fit, so I will do it myself. SDV8 AB MY 2020
MINI Cooper S Cabrio
Kit: Jaguar XK140 (in progress - the website is link to build)

This is going to be done under the extended warranty today. But the part couldn’t be found. The garage will call me on Monday. SDV8 AB MY 2020
MINI Cooper S Cabrio
Kit: Jaguar XK140 (in progress - the website is link to build)