Gravity Hull Designator/Sticky Entity

My initial goal was to find a way to apply Gravity Hull Designation to a vehicle so you could stand on it and drive without being effected, what I needed was the ability to place a prop or entity in the back of a truck and be able to drive without it flying around and flopping off. But, I am a TERRIBLE coder and couldn’t even get close to that. I tried to use the "“Sit anywhere script!” to allow multiple people to get on a car but it made your character invincible which is not a side effect I want. I am wondering if it is possible to make an object “stick” to a vehicle or how to apply a tool to a vehicle (For DarkRP) when it is spawned. Any help would be wonderful! Thanks!