I did sides only and it looks great! The ceiling glass is very dark from the factory and any extra tint would just black out the little bit of sky that does show thru. The un-tinted region of the back window is so small and sits directly above the large black rear shelf so it looks great without tint and offers plenty of heat/privacy protection. As you can see from Kamp's pic above, from the outside it's hard to even tell that there's an un-tinted region.
I did 3M Crystalline 50% on the sides and nothing anywhere else. It looks bitchin' and all limo blacked out but I wish I would have gone a little lighter (60% or so) because it makes the side mirrors very difficult to see. The tint makes the inside of the glass very reflective so during the day the dashboard reflection obscures both mirrors. And at night the auto-dimming mirrors can't be disabled so all you can see thru the tint is the faint greenish glow of some headlights.
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