https://www.nexusmods.com/carmechanicsimulator2021/mods/143/

I've been teasing it over the last few weeks but it's time for public test release.

In short, this mod allows adding new functional parts to the game:
- new parts (the parts that you buy in main shop, electronics shop etc)
- new tuned parts (tuned parts for vanilla parts or tuned versions of new parts)
- new Parts (this means the part assemblies you put in car configs in the editor)
- new Suspensions
- modify existing Parts and Suspensions (change, add, remove the parts in the assemblies)
- modify existing part models (meshes and/or materials)
- last but not least add new engines and modify existing ones.

The mod is designed to be as creator-friendly as possible. It is fairly easy to create variants of existing assemblies if you can navigate a 3D modeling program and a Unity project. I believe if you are able to make a bonus part you should be able to make a part for this mod.

Hope to see a lot of new content soon and let me know if you have any questions.