At least for me wayfinder online shop is still selling the product https://shop.wayfinder.com/category_show.php?catid=15

Other option is to buy used one. For example this should work also with N810 and as a bonus you get bluetooth GPS unit.

edit: Navicore Navigator software in the box itself doesn't work with N810 but the activation code should work. So all you need is the activation code.