>>15943557
Assettoland (just Google it) has lots of good car mods that you can't find on RD. They also update and improve existing older mods to fix bugs and make it compatible with current AC versions.
There's also a Facebook page called "Assetto Corsa Car Mods" (again, just Google it) that aggregates lots of cars and tracks, and it's updated regularly (you don't need a Kikebook account to use it). Even for years-old posts most of their download links still work.
There's an ongoing 5 year-old thread on GTPlanet which is another great source. It also has lots of good stuff and even tips on fixing broken / buggy mods yourself. They also post lots of tracks you can't find anywhere else. Again, just Google it.
Other than that, your best bet is to browse AC videos with content you find interesting on Youtube, lots of them include download links on their description. That's how I got lots of hard to find stuff, such as track rips from Grid, Grid 2 and Forza 7. And create a Kikebook account and subscribe to lots of subscription-only AC modding groups, I never did that since you'd have to point a gun to my head to make me create a Facebook account, but I hear people get lots of stuff you can't find anywhere else that way.
>pay mods would be nice since they are horse-armor tier considering the price being asked
I'd say nowadays the kikery in racing sim mods, especially when it comes to paid cars, is even worse than flight sims if that was even possible. At least most flight sim paid mods have real work, effort and research put into them. Lots of paid race sim mods have been proven to be based on ripped or stolen content.