RTM themselves have released a lot of their cars for free in AssettoLand. At least that is the impression I get, since their cars usually don't get taken down from that site. If that happens it's because the release was unwanted by them.
I don't want to be defensive of dubious modding practices, but honestly I believe there are far more interesting cars than talented people willing to bring them with high standards to AC. Some of my most favorite AC mods were ripped from other games. Am I proud of that? No, but if there's no other choice I will take it. And I think I'm taking a risk by saying this because the last time I said this (in RD) I got nothing but backlash. It's one of the reasons why I'm more active in this thread these days. At least here I don't get advertisement of fancy VR headsets, or high-end steering wheels I will never be able to afford getting thrown at my face, and potentially making me feel like crap. I already have more than enough reasons to be depressed.
Ultimately I'm just a mere casual AC player with none of that gear I've mentioned, and I just use this game to pretend I'm driving the cars I can only dream of owning in real life, but I know will never be able to even see, let alone be near of. I don't take this as seriously as other players and I believe I have the right to do so, because I bought this game. Everyone has their own opinions and ways of enjoying things. If some of you disagree with me, it's fine.