I just bought and installed an
A8 card that I purchased on Ebay for my
2016 ExPlat. The reviews for this Seller were all positive for this A8 SD card and I used Ebays' 'Make Offer' option with a lowball price - which the Seller took, got it in 3 days.
Installation was as easy as removing the A6 card and sliding in the new A8 SD card, it works fine and shows all the POI's and other data it should. My old destinations, favorites and other data was not removed, thankfully. Using the 'How to determine your SW version'
instructions found on this webpage it shows my Sync system software is compatible with the new A8 map software, in addition, the Map Database Version is shown as 'A8'.
So far so good but I will update this post if I find any abnormalities.