Load level depending on celected data

Hello!

I've got 2 scripts for selecting cars and spawning them in my game and I want to modify it. It works like this: Every car in the game has 2 prefabs (Unactive car without physics,Active car with physics and stuff) After choosing a car from array it loads level with the Active car that was matched to the Unactive car in the selection script

I want this script to have an option for level selection to(Like you can select track where the car will be spawned)

Here are my scripts so far

Selection script

 using UnityEngine;
 using System.Collections;
 
 public class CarSelector : MonoBehaviour {
 
     public GameObject[] carPrefabsGarage = new GameObject[2];        //car prefabs for garage
     public GameObject[] carPrefabsTrack = new GameObject[2];        //car prefabs for track
     public int carID = 0;                                            //number of selected car
     public GameObject carPoint;                                      //place where the car spawns in garage
     public GameObject currentCar;                                    //selected car. currently selected car.needed to spawn new on it's place
     public GameObject spawnPoint;                                      //place where car spawns on the map 
 
     void Awake()  {
         DontDestroyOnLoad(this.gameObject);
         if(GameObject.FindGameObjectsWithTag("ScriptPoint").Length > 1)  {
             Destroy(this.gameObject);
         }
     }
 
     void PrevCar()  {            //function activates when pressing "previous car"
         carID--;
         if(carID < 0)  {
             carID = carPrefabsGarage.Length - 1;
         }
         Destroy(currentCar.gameObject);            //deleting standing car
         currentCar = (GameObject)Instantiate(carPrefabsGarage[carID], carPoint.transform.position, carPoint.transform.rotation);        //spawn selected car
     }
     
     void NextCar()  {            //function activated when pressing "next car"
         carID++;
         if(carID > carPrefabsGarage.Length - 1)  {
             carID = 0;
         }
         Destroy(currentCar.gameObject);            //deleting standing car
         currentCar = (GameObject)Instantiate(carPrefabsGarage[carID], carPoint.transform.position, carPoint.transform.rotation);        //spawn selected car
     }
     
     void ToTrack()  {
         Application.LoadLevel("track");        //load track
     }
     
     public void SpawnCar()  {
             Instantiate(carPrefabsTrack[carID], spawnPoint.transform.position, spawnPoint.transform.rotation);        //spawn car prefab with physics
     }
 
     void OnGUI()  {
         if(Application.loadedLevelName.Equals("garage"))  {
             if(GUI.Button(new Rect((Screen.width - 200)/2, Screen.height - 100, 90, 50), "prev."))  {
                 PrevCar();
             }
             if(GUI.Button(new Rect((Screen.width + 200)/2, Screen.height - 100, 90, 50), "След."))  {
                 NextCar();
             }
             if(GUI.Button(new Rect(Screen.width/2, Screen.height - 100, 90, 50), "go to track"))  {
                 ToTrack();
             }
             GUI.Box(new Rect(Screen.width/2, Screen.height - 200, 200, 50), "selected car "+(carID+1)+" from "+carPrefabsGarage.Length+"");
         }
         if(Application.loadedLevelName.Equals("track"))  {
             if(GUI.Button(new Rect(10, 10, 100, 50), "to garage"))  {
                 Application.LoadLevel("garage");
                 Destroy(this.gameObject);
             }
         }
     }
 }
 

Spawn script

 using UnityEngine;
 using System.Collections;
 
 public class CarSpawner : MonoBehaviour {
 
     void Start () {
         CarSelector scriptPoint = GameObject.FindWithTag("ScriptPoint").GetComponent<CarSelector>();
         scriptPoint.spawnPoint = GameObject.Find("SpawnPoint");
         scriptPoint.SpawnCar();                //spawn selected car from CarSelector.cs when loading track
     }
 }
 

How can it be modified?