I thought about putting a sunroof in the backseat area. I went to a sun roof installer and they stated the it could be installed but could not promise a rain proof seal because the roof was not a smooth surface. It has grooves and would require that they be flattened. They also stated the roof might shift while driving and may possible cause small cracks where water can entered and leak in.

I just gave up from the point. My friends can just stick their heads out the window.