How to make object keep on their position when play button clicked?

Hai, I’m new with unity this is my first time doing project with unity. I want to make a racing game, as we know unity has that kind of game on it’s standard assets package. Now, my problem is I try to improve that standard packages by combining my own ground design and unity’s standard assets car script.

The First position :

I’ve done with rebuild and combining those elements, then I play the game the car position changing then I don’t have any idea about what happen like this :

Can somebody here help find out the solution? Thank you


There can be thousands of reasons causing this… You should give more info…

There is some script doing it?

There is some Animator doing it?

There is some collider+rigidbody ?