Freeze Position problem

On my car I have frozen its Y position so that when it collides with a tire it dosent go flying in the air, this works but for some reason when my car has hit a tire and is idle it starts wondering away without me pressing any buttons. Can anyone help me out?

I assume you’re using physics and rigidbodies.
You need to set the mass correctly on your car and the tyres. If you don’t want the car to be affected by hitting a tire make the mass of the car many times of the tyre.