Community Answers
-
The Englishman's post in Personnalisation trucks was marked as the answer
The window curtain can be found via the Mighty Griffin Tuning Pack found here: https://store.steampowered.com/app/461244/Euro_Truck_Simulator_2__Mighty_Griffin_Tuning_Pack/
Onced purchased you'll find it here when upgrading your truck: https://imgur.com/hk2WOWD
Hopefully this fully answers your query.