i dont know what sort of price or permament type of seeing through your glass is but other options i can think off is
1- vinyl up the windows the same color or black with the car
pros- are gives a little more security and cheap and easy to apply with loads o color options
cons-got no visibility and unless its good stuff you get a lovely glue goop on the windows
2- you may not have heard of or seen it before as its used for skining model planes for flight i dont know how good it would stick to glass think its called trans something or other cant remember the name havent used it in a while although i have a few rolls here ill see if its got the name on it
pros- are its completely transparent and avaialble in a huge selection of colors and cost around a fiver a roll compared to tint film which is around 20-30 a roll

it has to be ironed on so makes it a bit easier to put on things that are flat
cons are its not very protective as its designed to be as light as possible for model plane flight and i dunno if it will adhere to glass also it has to be ironed on which means extention cables out the house
found out the name

its a polyster film heat wrap there are a few companies that do it but the biggest is profilm
