How to keep the same distance betweeen 2 rigidbodies?

Like i have 2 gameObjects(pair of front wheels,and pair of back wheels) how to keep the same distance between them

One way would be to add a fixed joint between them so they are stuck together
Tho I am not sure if it’s a good approach to make a vehicle

Actually gluing together 2 pairs of wheels won’t do the trick, but you can connect their parents, or even better, make both pairs having same big car parent, through different joints. I guess you would need some kind of rotating one for the front pair and regular fixed to the back pair? Can’t provide a coherent solution but you should definitely look into joint components

Edited Code

public class CarWheels : MonoBehaviour
public Rigidbody frontWheel1;
public Rigidbody frontWheel2;
public Rigidbody backWheel1;
public Rigidbody backWheel2;

private float initialDistance;
private float moveSpeed = 5f;

void Start()
    initialDistance = Vector3.Distance(frontWheel1.position, frontWheel2.position);

void FixedUpdate()
    float currentDistance = Vector3.Distance(frontWheel1.position, frontWheel2.position);
    float scaleFactor = initialDistance / currentDistance;

    Vector3 newBackWheel1Position = frontWheel1.position + (backWheel1.position - frontWheel1.position) * scaleFactor;

    Vector3 newBackWheel2Position = backWheel1.position + (backWheel2.position - backWheel1.position) * scaleFactor;

    backWheel1.position = Vector3.Lerp(backWheel1.position, newBackWheel1Position, moveSpeed * Time.deltaTime);
    backWheel2.position = Vector3.Lerp(backWheel2.position, newBackWheel2Position, moveSpeed * Time.deltaTime);

Maybe something like this could help?