Then he found it: a link on a German forum, buried deep in a thread about VAG-COM cables and firmware updates. The file was called Audi_RNS_E_Navigation_Plus_Maps_Europe_2020.rar .
A desktop tool for managing navigation SD cards. Purpose: To simulate how the RNS-E unit processes routes before the user even gets in the car, preventing "Route calculation not possible" errors commonly found when updating maps. Audi Rns-e Navigation Plus Maps Europe 2020.rar