Well, this is a question of scope and how the car racing game economy works in general.
The root of the problem is that American intellectual property right allow the owners of the original article to control use of a scale model, including computer models. There are lots of discussions about this from before computer games were big, where scale models including plastic kits had this big discussion going on whether they would be required to get a license for a scale model of a P-51 Mustang. And if so, after what kind of period the right to contol would expire (patents expire, trademarks do not).
Now in the 3D worls, the racing game companies have to license (or at least feel they have to, I'm not sure this has been tested in court). As a result you do not only have absurd mixes of cars in games (Assetto Corsa without a single Porsche according to non-mod state for how long? Please. That is ridiculous). We also have the manufacturers execute more control over the game releases than just design and names. It is obvious that the licenses that are given to Assetto Corsa are not only heavily influenced by marketing wrt which cars come out, it should also be clear to everybody who drove those cars in real life that there are very odd dynamic characteristics by manufacturer inside the game that do not exist in the real world.
It also leads to really annoying wasted work such as in the M6 GT3 which is probably finished inside Kunos but BMW prefers to pretend the M6 GT3 never happened and moved on to the M8. Same for the Mercedes Sauber C9 sprint version, which at least didn't waste a 3D model.
How do the gamers react? They redistribute all games' cars to all other games. And sometimes pretty badly. If you play by Kunos rules you are not allowed to read their own physics definitions so how do you get it right? Inside the game companies the same cars, that happen to be licensed, or at least are likely to be still licensed when they can be released, are done over and over by 3D artists. Which I suppose at least creates jobs.
Now gamers who want a collaborate effort have to start from their own 3D models. That would be a lot easier if people didn't waste their time copying game cars, which cannot be used for collaborative efforts (on github or whatever).
A person who really wants a specific car now needs all of the 3D modeling and physics skills (textures are probably coming easily after you release the thing). Paying somebody to do all this is $$$ and -worse- cannot be used straight for all games. The person who contracts making the 3D model needs to target one game to have a clear contract objective.
This is just idiotic. The cars should be developed like Open Source software. OSS is not released because people don't want to get paid for making tools. OSS exists because programmers wanted to stop worrying about their basic tools and spend their energy on something original instead, so they just share the tools so that the tools are developed only once in total. Instead of everybody first making all the tools, badly, and then running out of steam before actually useful work happens.
So a car's game model should be on github where all the text files (physics etc) can be hacked up for multiple games at will. The 3D model is a bit more tricky since it cannot directly be broken up into diff/patch/merge'able files. But as a starter a 3D model for one game would do, because as we see there is no shortage to make at least one-short ports of the 3D model to the other games.
License wise I estimate it would be a good starting point to:
- not use the car manufacturer's name
- not use the car model's name
- not use the car manufacturer's logo
- not use the car manufacturer's grille design
In the version that is committed to the central repository that is.
I can say that I would contribute $200 toward a 3D model of the F12 6-series that is detailed enough so that it can be used in multiple currently existing games, has a specific model export for AC right now, comes with a true open source license (GPL, MIT, BSD or whatever), is somewhat modular (wheels, controls etc are delivered separately) and has a basic set of variants (wider winged up version for GT3 is default, street fenders and lids are provided, maybe street interior, too).
Just putting my money where my mouth is. The F12 6-series is probably the oddest release that BMW did in the last 15 years, but there is some basic flair around it. And let's face it, BMW wants this thing forgotten, they will never allow releases, and I want to stick it to them.