When the vehicle is put into drive mode and another player walks up to the vehicle, he/she can push it around like it weighs nothing. They can also jump on it and cause it to be pushed up and fly all around. This is caused by the infinite mass kinematic character controller.
My question is, how did other people solve this and what is the right direction for me to go in?
Currently, to avoid the problem, I put a box obstacle around the vehicle. However, this is not a long term fix. Can someone point me in the right direction?