"Ingaming" a model as a working truck?

[Digital X]

I've been chasing this dream for goodness knows how long and still cannot figure it out. I just want to know the absolute minimum I need to do to get a working truck into the game from Blender.

What locators do I only NEED for it to show? Like the interior locator node on the outside cabin, the driver locator etc. I know this is a big ask but I've tried so many times and got nowhere. I'm sure I can write def files for it to pull pieces from a man tgx for example right? Like the in the truck_desktop folders.

I know about wheel_f_0 etc for the chassis, is that another thing I can pull from pre-existing defs or is it better to make everything from scratch and follow a mod folder's layout for example?