i used these guys off ebay, pre cut tint. its dyed but my back window is still black a year later. they sell the whole car for like 40 bucks. one big piece for the back window, they also sell brow strips.
you can also order any combo of tint % you want, 35% up front, 20% rears. what ever you want.
i got the 20 % back window and a 5 % brow for about $20 i think.
items in Precision Window Films Automotive Precut Window Tint Kits store on eBay! i also pm'ed them and they are a shop in FL this is the tint they sell and install on their customers cars. they also ship quit fast.