Replacing textures

Hi, so I am busy with my UI and I got stuck on this one problem.

I have 10 cars(just for testing) and there are 2 textures for each car. I have created a rectview to scroll thru the cars with the arrow keys. So I got it all working but, I need the current car that is selected to have a different texture(which is carSmallBox1 in the code). Can someone guide me to possible solution or an a idea that I can try. The link has the images if you want to test out the code(note, the textures with a 2 in front of the name like "2TestCube" is the textures for carSmallBox1[]), just set garageIsActive to true if you want to test it out. If you need me to explain anything, please ask.

Here is what it looks like.

The code: using UnityEngine; using System.Collections;

 public class Garage : MonoBehaviour {
 
     /*Create Textures*/
     public Texture[] carSmallBox1 = new Texture[10];
     public Texture[] carSmallBox2 = new Texture[10];
     //private Texture carSmallBoxCurrent;
 
     /*Create Rect for gui elements*/
     private Rect[] carSmallBoxRect = new Rect[10];
 
     private bool garageIsActive;
     private int amountCars = 10;
 
     /*Create variables to determine the locations of the GUI elements*/
     [SerializeField] private float bottomBarCarsx; // This value will dtermine the legnth of the amount of cars in the x axis(returned as pixels)
     [SerializeField] private float bottomBarCarsy; // This value will dtermine the legnth of the amount of cars in the y axis(returned as pixels)
     [SerializeField] private float bottomBarCurrentx; //This value will determine which car is currently selected and to help with scrolling
     private float maxBottomBarCurrentx;
 
     private int currentCar = 0;
 
     /*Create the needed variables to determine the size of the scroll view rect*/
     private Vector2 scrollPos;
     private Rect scrollRectPos;
     private Rect scrollViewRect;
 
     /*Create the need variables for screen locations and screen resolutions*/
     private const float iconWidth = 70;
     private const float iconHeight = 100;
     private float screenWidth;
     private float screenHeight;
     private float nativeWidth = 1024;
     private float nativeHeight = 597;
     private float nativeWidthCentre = 512;
     private float nativeHeightCentre = 298.5f;
     private float rx;
     private float ry;
 
 
 
     void Start () 
     {
         screenWidth = Screen.width;
         screenHeight = Screen.height;
 
         bottomBarCarsx = nativeWidth/2;
         bottomBarCarsy = nativeHeight - 150;
         bottomBarCurrentx = 0;
 
         scrollRectPos = new Rect(0, nativeHeight - 150, nativeWidth, 150);
         scrollViewRect = new Rect(0, nativeHeight -150, nativeWidth +300,100);
 
         /*Determine the rx and ry(i dont know what they stand for) for the matrix*/
         rx = screenWidth/nativeWidth;
         ry = screenHeight/nativeHeight;
 
         for(int i = 0; i < amountCars; i++)
         {
             carSmallBoxRect[i] = new Rect(bottomBarCarsx, bottomBarCarsy, iconWidth,iconHeight);
             bottomBarCarsx += 100;
         }
 
         maxBottomBarCurrentx = (amountCars*200) - 200;
 
         scrollViewRect = new Rect(0, nativeHeight -150, bottomBarCarsx + 410,100);
     }
     
 
     void Update () 
     {
         garageIsActive = HomeScreen.test1Bool;
     }
 
     void OnGUI()
     {
         /*Create a new gui matrix to automatically scale all gui elemnts for any screen resolution*/
         GUI.matrix = Matrix4x4.TRS (new Vector3(0, 0, 0), Quaternion.identity, new Vector3 (rx, ry, 1));
 
         if(garageIsActive)
         {
         scrollPos = GUI.BeginScrollView( scrollRectPos, scrollPos, scrollViewRect);
 
             for(int i = 0; i < amountCars; i++)
             {
                 GUI.DrawTexture(carSmallBoxRect[i], carSmallBox2[i], ScaleMode.StretchToFill, true, 0);
             }
 
             GUI.ScrollTo(new Rect(0, nativeHeight - 150,1025 + bottomBarCurrentx, 150));
 
             if(Input.GetKeyDown(KeyCode.RightArrow))
             {
                     bottomBarCurrentx += 100;
                 if(bottomBarCurrentx > maxBottomBarCurrentx)
                     bottomBarCurrentx = maxBottomBarCurrentx;
                 currentCar ++;
             }
             if(Input.GetKeyDown(KeyCode.LeftArrow))
             {
                 bottomBarCurrentx -= 100;
                 if(bottomBarCurrentx < 0)
                     bottomBarCurrentx = 0;
                 currentCar++;
             }
         GUI.EndScrollView ();
 
         }
     }
 }
 

The link for the pictures: https://www.dropbox.com/s/1zypu1g1ofimiig/Assembly%20Bay%20Pics.zip?dl=0