Retail edition can now get the latest update for ETS2.
SCS Blog said:The recently released update 1.13 for ETS2 is now available for retail users on the ETS2 update page.
The main feature of this update is support for Steam achievements. Achievements aren't available in the retail version, so if you want to add this bit of additional challenge to the game, you will need to activate your retail key on Steam. We've published instructions on how to do it on the World of Trucks site.