MAY, 2024:
This is now implemented in the cheat menu, if you want this and any other future vehicles,armor..etc then goto the link below.
Using the sophisticated method to extract the needed files to get the vehicles in game, before release, you can see them. The sound is buggy and looks like the Mech needs a Controller, i use K&M..nm it was my menu setting:) check out if you want rapid fire,and alot of other goodies :)
*update* After the recent patch, the mechs/vehicles can no longer be edited into the game easily, youll have to purchase a menu to unlock them and many more features if you want