with out me going into other peoples video’s the bottom line afaik is that your “root” bone of the rigg must be at 0,0,0 , if you have for any reason scaled or moved the rig/mesh the reset the root bone
ps haven’t tried much on the vehicle side due to the lack of base code, without basics like multi-wheeled / hover / copter/ flyer there not much point in me trying things of doing tutorials