You cut the tint to the size you need for the rear glass w/ about 2-3 inches of extra on top and bottom and sides.use a heat gun to shirnk it to fit the contour using the card in your kit and regular soapy water works great, you dont need their tint lubricant spray, its probably just soap anyways....... its kinda almost an art to shrink it to fit the contour of the glass. if you look at the rear glass its not flat it has some curve to it. i have watched my tint guy do it a million times and he is super good at it. and i dont think it is something i can explain, you really have to see it done to get a grasp on it. the video didnt talk about shrinking it? then how do they suggest you make it fit the contours of curved glass

do they say use multiple pieces of tint?
sorry man i am not much help on the subject i have just seen it done. if you figure out how to do it you might want some extra for when you mess up.
how much did you pay for the kit?????