Vehicles: Overview & Car Setup

Hey, Was hoping you guys can give me some support regarding the wheeled vehicle class not working for my custom car.
Works perfectly fine with the car the intructor gives on youtube but any other car just doesn’t work.
Please HELP!! I’m freakin out, vehicle class is awesome but not if you can only use it with default assets!!.
I’m attatching my fbx for you guys to check out!!