This is a vehicle physics system for the Unity engine, originally developed with Unity 5.6. The most recent Unity version it has been tested with is 2019.2.9. It aims to achieve semi-realistic, general-purpose driving mechanics. This was originally sold on the asset store as Randomation Vehicle Physics 2.0.
You may contribute by first pulling the repository into your own fork where you can add commits, then creating a pull request to merge your changes. After a pull request is approved, it can be merged into the master branch.
If you feel up to it, you can try tackling one of the issues in the issues tab above. You are free to put comments around your code giving yourself credit if you feel compelled to do so. If you add new properties/variables when contributing, make sure their default values do not change the behavior of the included prefabs. Any added code will be considered to be under the MIT License as the rest of the repository is.
Documentation can be found in the manual.
Import the repository into the top level of a blank Unity project folder to make sure everything works. After that, you can attempt to import it into your own project, but be mindful when merging the project settings. Read the section of the manual about project settings to make sure you copy the ones that are important and address potential conflicts with your own project settings.
Code is licensed under the MIT License. You can sell projects that use code from this repository as long as the MIT License is included with indications that it applies to the original code here. Valid commercial projects include compiled applications and/or "assets" containing uncompiled source code. As long as the code from this repository is not being sold by itself, what is being sold is most likely permissable. Basically, it must include substantial modifications and/or additions.
All models and textures are public domain and were created for this package.
Font:
Roboto under the Apache license http://www.google.com/fonts/specimen/Roboto http://www.apache.org/licenses/LICENSE-2.0.html
Sounds are from freesound.org, some of which are public domain, others are under either the Creative Commons Attribution license or the Creative Commons Sampling Plus license.
http://creativecommons.org/publicdomain/zero/1.0/ http://creativecommons.org/licenses/by/3.0/ http://creativecommons.org/licenses/sampling+/1.0/
Sound links:
Engine: http://www.freesound.org/people/cr4sht3st/sounds/157144/
Hover Engine: http://freesound.org/people/larval1977/sounds/38488/
Boost: http://www.freesound.org/people/pengo_au/sounds/90143/ http://www.freesound.org/people/ftpalad/sounds/119902/ http://www.freesound.org/people/snakebarney/sounds/138101/
Hover Boost: http://freesound.org/people/LG/sounds/14585/ http://freesound.org/people/ejfortin/sounds/49693/ http://freesound.org/people/vrodge/sounds/119499/
Tire Screech: http://www.freesound.org/people/audible-edge/sounds/71739/ http://www.freesound.org/people/audible-edge/sounds/71738/ http://www.freesound.org/people/audible-edge/sounds/71737/ http://www.freesound.org/people/audible-edge/sounds/71736/
Collisions: http://www.freesound.org/people/Halleck/sounds/121622/ http://www.freesound.org/people/Halleck/sounds/121656/ http://www.freesound.org/people/Halleck/sounds/121658/ http://www.freesound.org/people/Halleck/sounds/121623/ http://www.freesound.org/people/Halleck/sounds/121657/
Tire Pop: http://www.freesound.org/people/Gniffelbaf/sounds/82121/
Rim Collision: http://www.freesound.org/people/dheming/sounds/177781/
Rim Scrape: http://www.freesound.org/people/UncleSigmund/sounds/30640/
Tire Air: http://freesound.org/people/Adam_N/sounds/164623/
Glass Break: http://freesound.org/people/m1a2t3z4/sounds/112213/