Force car to fall straight down without spinning

I have a simple 3d box car with a rigidbody, collider, and move with rb.MovePosition. How do I force the car to be in a stand-up straight position while falling and not spin in the air? If I use rigidbody rotation constraints to freeze rotation, the car won’t line up with the ramp when going up.

Here is a script (warning pseudocode) that freezes the roation in the air when the car detects it is in freefall. Should show you the basics of how to implement something like that:

using UnityEngine;

public class CarFreefallConstrains : MonoBehaviour
{
    private Rigidbody rb;

    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }

    void FixedUpdate()
    {
        if (rb.velocity.y < 0f && !IsGrounded())
        {
            rb.constraints = RigidbodyConstraints.FreezeRotationX | RigidbodyConstraints.FreezeRotationZ;
        }
        else
        {
            rb.constraints = RigidbodyConstraints.None;
        }
    }

    private bool IsGrounded()
    {
        RaycastHit hit;
        if (Physics.Raycast(transform.position, Vector3.down, out hit, 1f))
        {
            return true;
        }
        return false;
    }
}