City Navigator Europe NT 2016.10
I don't know when it was released, but anyone with Garmin nüMaps Lifetime™ Europe should now be able to download the latest version of City Navigator Europe NT, which is version 2016.10.
I did so yesterday, but NOT by using Garmin Express! The older, more reliable Garmin MapUpdater worked fine; I installed UK and Ireland directly to my nüvi660 and the rest to my computer. Then I created a custom mapset for the near continent using Garmin MapInstall - a tedious process which took over an hour. To transfer the mapset to the GPS took another 90 min, but eventually all was fine.
Garmin prefer people to use Garmin Express but, as I mentioned earlier, a lot of people have had problems with Express.
I'm not sure whether the aera500 is compatible with MapInstall though...