Hi Daniel - thanks for giving SkookumScript a spin! Plugins shipped with the editor are just like any other plugin. You simply add a line
SkookumScript.ini in either the plugin folder (this works only if you build the engine from source) or, preferably, your project folder, and all the PhysXVehicles plugin functionality should be available via SkookumScript.
SkookumScript integrates into the build system automatically (specifically, into
UnrealHeaderTool). The plugin piggybacks onto
UnrealHeaderTool, scans the default engine modules and your game modules for reflected C++ classes and makes those available via SkookumScript - both to the scripting language and to the REPL.
You can use the REPL any time without having to modify your project. The SkookumScript files necessary for this are stored in your project's
Intermediate folder where they don't affect your project's content, or your teammates.
Let us know if you have any more questions!