Tilting A Hover Car, need to lock the rotation

So I have a vehicle(ripped right out of the unity sample file, and a tutorial from youtube (- YouTube) So here’s wha

When i turn the vehicle, i want it to tilt into the turn, much like Wipeout. The problem is, whenever you apply the force, it continues to rotate. I tried Mathf.Clamp, but i think im grabbing the wrong things here. Code from project:

using UnityEngine;
using System.Collections;

public class HoverController : MonoBehaviour {
	public float speed = 90f;
	public float tiltAngle= 0f;
	public float tiltForce = .001f;
	public float turnSpeed = 5f;
	public float hoverForce = 65f;
	public float hoverHeight = 3.5f;
	private float powerInput;
	private float turnInput;
	private const float MAX_TILT = .1;
	private Rigidbody carRigidbody;
	void Awake () 
		carRigidbody = GetComponent <Rigidbody>();
	void Update () 
		powerInput = Input.GetAxis ("Vertical");
		turnInput = Input.GetAxis ("Horizontal");
		tiltAngle = turnInput * tiltForce;

	void FixedUpdate()
		Ray ray = new Ray (transform.position, -transform.up);
		RaycastHit hit;
		if (Physics.Raycast(ray, out hit, hoverHeight))
			float proportionalHeight = (hoverHeight - hit.distance) / hoverHeight;
			Vector3 appliedHoverForce = Vector3.up * proportionalHeight * hoverForce;
			carRigidbody.AddForce(appliedHoverForce, ForceMode.Acceleration);
		carRigidbody.AddRelativeForce(0f, 0f, powerInput * speed);


You probably need to add some angular drag to the rigid body. If angular drag is zero, there’s no angular friction to counteract the force added by AddRelativeTorque(), and the rigidbody will rotate forever.