Look man, I don't care if modders outside of AC such as GTA ones go steal cars including modded ones, even tho I totally despise that franchise for a reason I will come to a bit, at least they too get tons of cars to drive with. (As long as they might ask for permission from each author, which sadly they all don't do so at all...)
Encryption in AC to me is hit and miss, while it may be totally useful for modders who make scratch-made cars like the ones in RaceDepartment since they put effort and love into them, it totally doesn't make sense to some other modders who convert cars from other games and 3D model sites too rarely (and mostly edit them too with either scratch-made or taken parts added in) who badly want to OVERprotect almost all their stuff they make, thinking like their life depend on them or something like that, while in reality of course it is not and originally belong to a game developer/3D models website/modeler. Hell, I saw one on FB days ago who was going to release a modern Bentley Continental GT surely converted from another game, but not until he wants it encrypted like a friend of his told to us, and some admins there said that if it remains private until so, then it shouldn't be shown there at all by their rules.
I honestly starting to HATE this new millenial generation of modders, which I'm entirely sure it came out of that damned franchise over the years which probably splitted the modding community between those I mentioned, the ones who do it JUST for money via commissions from others (which in turn many cars remain private of course) and those who just wanna selfishly and completely keep their stuff private all to themselves (like a notorious FB group all about rally cars and sometimes touring cars too). Where did the whole harmless nature of modders during the rFactor/GTR2/GT Legends/RACE 07/RBR era go? Back when ALL modders created mods for passion, effort and love for cars, being all willing to share them to anyone for free, not being afraid and aware of other pesky modders who stole them and converted them for other games (that kind was unheard of back then). And private mods where only used for championships and events which were all predecessors to E-Sport events we got today, infact the very first time in my life I saw private mods used for selfish reasons was with those badly scratch-made JDM drift cars for GTA SA which are still visible in some moddders' personal retro blogs which aren't updated anymore at all.