#Finbarr - There is no /update folder anywhere on the SD card and I have viewed it with hidden/system files showing. I attach image showing root but I have explored every sub directory on the SD card. I'll also advise that the Apple Carplay is not installed from the Sat Nav software SD card as the only things on the card are Navigation related.
As you are a software engineer it would be great if you could write software that could clone these cards successfully so a backup could be produced. Every attempt, with lots of cloning software, has failed for me every time - if memory serves me correctly they all produce an image or clone that is 1k larger than the SD card ..... or it might be smaller!