All marketplace developers do have some contact listed, as per the old marketplace EULA, and you can find theirs here. That said it looks like they made updates and extensions to their vehicle setup but it seems to be in their paid assets here.
It shouldn’t be too difficult and I have two video resources showing the setup with some other vehicles. It seems like the older UE4 rig setup works for Chaos as well, but you may need to edit it if not. Here’s a tutorial that goes over the basic setup and some supporting documentation:
Documentation for Chaos vehicles:
https://dev.epicgames.com/documentation/en-us/unreal-engine/vehicles-in-unreal-engine?application_version=5.4
Disclaimer: One or more of these links are unaffiliated with Epic Games. Epic Games is not liable for anything that may occur outside of this Unreal Engine domain. Please exercise your best judgment when following links outside of the forums.