https://forums.seatcupra.net/index.php?threads/navigation-system-updates.388586/page-53
There's a very long thread here.
But assuming you have an MIB2 standard system with the sd card. Then follow the steps and use the links in the latest posts on that thread to download the newest maps etc from november 2019.
TAKE A COPY OF YOUR EXISTING SD CARD FILES AND KEEP THEM SAFE.
Can't stress that enough. You will need to copy the new nav files to your existing sd card and then copy your existing overall.nds file back onto the card. If you forget to take a copy of your existing files, it's an expensive trip to the dealer.
Goto page 99 on that thread and work up. November 2019 release is available. 1430. Follow notes !.
The standard Seat navigation uses TomTom cartography. The Plus unit Here Maps.
The standard ones when shipped can go out with old maps. There was an issue in the release a couple of years back which is now sorted where it assumed you were towing a trailer and you got trailer speeds. Think Seat bungs them out with 1030 on them before the issue which is now fixed. June 2018 release was 1030 standard release.
Google cartography isn't the bees knees. There are areas where the maps are out of date due to them not sending survey cars around and using old satellite images so can't validate what is crowd sourced so they reject users reports of changes. You can't draw the road map changes on either, just tell them where they are. TomTom seems better on getting survey cars out but doesn't allow map drawing but takes on-board comments... upto September 2019. Here maps allows drawing, up-to-date sat images, survey cars, uses crowd sourcing to validate.
Google scores on real time information gained by other Google map users progress. Others rely on different road observation systems fed into TMC. Real time versions in some stand alone systems. Timing issue with TMC. Internet connected systems are said to be faster using the same TMC data but faster refresh. Not rolled out to Seat yet. SIM card in the unit for that. On VW cars.
Obviously the publication of the maps is faster on Google but if roads are missing an issue. It's new housing estates that get left off these systems. The core teams know about road developments but not new housing builds. The achilles heel in terms of how they get their information if they aren't getting survey cars around to update, have good quality timely sat images and a base of crowd sources. They do also uses other techniques of scanning competitors maps to generate error reports plus analysis of mobile phone tracks. The UK gold standard cartography is the commercial OS local level survey data that they dont buy into, but look at for validation, but published yearly.
Hope that helps.