Because I read, listen to music, visit with friends, etc. at night, I'd suggest for privacy, getting curtains. I have limo tint which is quite dark, and with interior lights on at night, it's easy to see the interior from outside. Daytime is a very different story. 

Id suggest putting in a silver socket or 2, and some USB ports if your kids like playing computer games or watching DVD's, unless you have a screen/display already mounted up front just behind the front seats. 

Investing in adding LED interior lighting is useful. Superbrightleds.com is a good resource. 

Slider and rear hatch screens are invaluable on hot summer nights. Also consider replacing the OE tent with a 3-window version for the dramatic circulation improvement. 

Bob