Verify Planes collision inside OnMouseOver of another GameObject

I have a script attached to a plane (the background of my 2D game) that creates a Prefab and when the user moves the cursor, this Prefab is shown on the current mouse position. This is working fine but now, I have some other Planes above the background and I want to hide my Prefab when it is over one of these planes.

All the planes over the background and the Prefab created (that is also a plane) have a BoxCollider

Here's my code so far:

 void OnMouseOver() {
     ChooseTower inst=ChooseTower.getInstance();
     string prefab=inst.prefabToPlace();
     if (prefab!=null){
         Vector3 mousePos=Input.mousePosition;
         Vector3 cameraPos=Camera.main.ScreenToWorldPoint(mousePos);
         cameraPos.y=2;
         if (current_tower!=null)
             current_tower.transform.position=cameraPos;
         else {
             current_tower=(GameObject)Instantiate(Resources.Load(prefab),cameraPos,Quaternion.identity);
         }
         current_tower.renderer.enabled = true;
         foreach (GameObject rectangle in Levels.path.getRectanglesPath()){
             if (current_tower.collider.bounds.Intersects(rectangle.collider.bounds)){
                 current_tower.renderer.enabled = false;
                 break;
             }
         }
     } else if (current_tower!=null){
         Destroy(current_tower);
         current_tower=null;
     }
 }

This code kind of works with Planes that are not rotated. But my problem is that I have some Planes that are rotated and here, it detects collision where it doesn't exist. So maybe I cannot use collider.bounds.Intersects but, I don't know what else I can use... I simply want to verify if a plane is colliding with another on mouse over using BoxColliders on both planes. How can I do it?