Okay I have a work around but it's not pretty.  This looks like the right way to do it but it destroys the map each time...  so there's no way to just control the visibility with a map loaded with markers and polygons.

 if (fragment == null){
        	fragment = new MapFragment();
        	
        	 GoogleMapOptions options = new GoogleMapOptions();
        	 options.zOrderOnTop(true).mapType(GoogleMap.MAP_TYPE_HYBRID);

     		// Define new bundle with options
     		Bundle arguments = new Bundle();
     		arguments.putParcelable(MAP_OPTIONS, options);
      
     		// Set arguments to this instance
     		fragment.setArguments(arguments);
     		googleMap = fragment.getMap();

        }
...

    	  _savedCameraPosition = fragment.getMap().getCameraPosition();
    	  FragmentManager fragmentManager = getFragmentManager();
    	  FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
          fragmentTransaction.remove(fragmentManager.findFragmentByTag("MAP"));
          fragmentTransaction.commit();
          fragmentManager.executePendingTransactions();

I have to remove the mapFragment every time which wipes all the markers... so I have to re-add them and re-load the map every time.  But it seems to work well enough for now and I can even control if the map goes on top of the camera feed.

Thanks for your help!  It's always appreciated!

The child GLSurfaceView seems to deactivate the Unity Layer as well.

This is rough.  I'm seriously getting stressed here...

Is the Background Texture Access sample performed on the java side of things?  I'm getting a sinking feeling that this might not acutally be possible the way I'm trying to do it.  But I'm not sure how else to use a unity interface to switch between the Vuforia camera and Google Maps v2.

The QCARView is an instance of QCARUnityPlayer, so if you remove that view, you will loose the Unity view (and the buttons with it);

if you search among the children, you could check whether you find an instance of GLSurfaceView.

Okay, just because this could be up and running in one line of code (rather than redoing it all from scratch), I've tried the following:

qcarParentView.removeView(qcarView);

But the Unity Buttons also disappear.  Is the camera view a specific child of the qcarView I might be able to add and remove?

I believe the Unity GUI buttons are rendered on top, not on the same GL surface view;

perhaps you may want to try the Background Texture Access sample, which uses a different method to render the camera view.

Yes, but it doesn't work as expected.  The map UI controls appear and are clickable (meaning the view is likely already in the front) but the conflict seems to be with the GL rendering on the surface view.  Is there a way to access the Vuforia surfaceview directly to toggle the camera feed on or off without losing the Unity GUI buttons?  Something along those lines would probably be sufficient for what I'm trying to do.

Maps doesn't allow for ZOrder to be set.

I'm resigned to not using the Vuforia and GoogleMaps SurfaceViews at the same time but are the Unity GUI buttons also being rendered on that surfaceview?

Have you tried using the method bringToFront() on the map view ?

Another possiblity is to try using setZOrderOnTop(true) on one of the SurfaceViews;

Note that mixing SurfaceViews in Android is known to be problematic in general.

Within spitting distance of my goal but the glitch with the map and camera not showing up exactly how I need them to has lead me to discover this:

http://stackoverflow.com/questions/15370624/mapfragment-and-camera-seem-to-interfere-with-each-other-in-the-same-activity

Apparently it's a conflict between 2 surfaceviews.

Now I have to learn how to incorporate two activities in the same app.  

Two weeks of work and nothing to show for it...  I think my head is going to explode.  

What happens if you deliberately background and then foreground the app? - same behavior?

Yes, and infact I can see the map flash for a brief second before the app enters the background.  Then when it's in the foreground the map appears.

Maybe I'm going about this incorrectly... I do need to be sure that the map is Overlapping the camera feed/Unity in the background otherwise I'm not able to set the margins correctly/dynamically.  I'm not currently working with a layout but should I be using a layout as an intermediary?  Should a Layout be added to the QCAR parent view and then add the map over that to ensure there can still be some of buttons from Unity appearing at the bottom edge of the app?  Sorry for all the questions.  I'm so maddeningly close to cracking this...

What happens if you deliberately background and then foreground the app? - same behavior?

Let's see what Alessandro has to say when he gets back online. But it's good to see that you've gotten the map to render.

Yes, I've followed them to a tee, and I just figured out what i was missing.

  //if QCAR view has been found, add some android view/widget on top
              if (qcarView != null) {
                  ViewGroup qcarParentView = (ViewGroup)(qcarView.getParent());
                  FragmentManager fragmentManager = getFragmentManager();
                  FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
                  MapFragment fragment = new MapFragment();
                  fragmentTransaction.add(qcarParentView.getId(), fragment);
                  fragmentTransaction.commit();
                  
                  //  View myView = getLayoutInflater().inflate(R.layout.mymap, null);
                 // qcarParentView.addView(myView, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
                           
                  mQCARView = qcarView;
                }

Because getLayoutInflater().Inflate seems to explode when handling a map fragment.

However, a new issue has presented itself.  When the app first launches, all I see is the vuforia app and the +/- scale buttons for the map, but when the app goes to sleep and wakes up, the app appears correctly (or at least at this point it appears Above the Vuforia camera feed).

Any thoughts on what could be causing that?

Have you seen - https://developer.vuforia.com/resources/dev-guide/extending-unity-android-activity-and-adding-custom-views-eclipse

and

https://developer.vuforia.com/resources/dev-guide/extending-unity-activities

and some other helpful articles - https://developer.vuforia.com/resources/dev-guide/knowledge-base-articles