Just to clarify, you're talking about the ground units? i.e. the hummer, mercedes wolf, etc?
Cause the helipads, ships, cargos and the landing truck seem to work just fine.
By "working" you mean showing up in game?
If so, you also need to download the "Scripts" and "MissionEditor" folder from his dropbox: https://www.dropbox.com/sh/x6gmq6z2ezsmrgu/AAAMK3Hid2LgEVF-RFIBb4Gxa/game%20folder?dl=0&subfolder_nav_tracking=1
These 2 folders go in the main directory, not the saved games folder. Better use a mod manager.
They are just eye candy tho.
Also, if you want to hide these lovely pylons we all love while using one of upuaut's attachment for the huey, you can add this at the bottom of the description.lua of a livery of your choice
custom_args =
{
[1000] = 1.0,
}