My car looks broken when i drive away (VIDEO)

Hello people I am trying to make my first car (modify an original one and I am trying to transform it into a police car) I always wanted and had the dream of achieving 100% completion of my first car and with it learn everything that entails making a car like this .

But I find myself with several problems 1- English is not my main language so it is much more difficult for me to understand certain things.
2- I am not an expert in zmodeler3 (haha)

When I drive away this happens to me, what could be the problem?

I fixed it by changing the value of the first LOD in the vehicles.meta from 15> 350 BUT !!! As I understand it is not the best way to solve it, I see people who make these cars and have no problems with that and have no need to modify the vehicles.meta Then I would really like to learn how to solve that correctly,.
please help!