Window films are manufactured several different ways that offer different forms of protection. Ceramic,Metal,Carbon and IR films are examples of high end films.
Film removal is expensive due to the labor involved. A lot of it. It usually takes 2-3 times as long to remove it then install it. Its messy and labor intensive. And not done right can result in scratched glass,defroster and antenna damage.
Why do you need a lifetime warranty? A manufacturer lifetime warranty covers Fading,Defects,Distortion,Discoloration & De lamination. In climates that have high heat and a lot of sunshine these warrantys are important in the rare case they fail in such a harsh climate(Like PHX). You may not keep your car forever but want to be protected as long as you have it. Better film/Better warranty/Better protection. Any shop can offer a warranty but without it being backed by the manufacturer and by not using higher end film the chances are good the film will fail and you will have to have it replaced.
Why may you get high quotes? There is a shop that i seen that will do you vehicle for $99. Most $99 shops are not reputable , offer no warranty and are using cheap "dyed" plastic films that offer little heat protection. This films usually lasts a year or so before turning purple or bubbling up. The more protection for your ride, the more expensive the film. We cant stress enough not to cheap out on window film. Your vehicle is expensive,protect it!
Why is your car more expensive then any other? Its small? The size of a vehicle is irrelevant. Old cars take more labor to install film then new ones. Smaller cars tend to have more windows then bigger vehicles. Some vehicles have very curved glass(that may look flat) . Glass placement,how many windows,age of vehicle and sometimes type of vehicle are all factors in a tint quote.
Can windshields be tinted? Yes-its very popular,but it is an additional charge to your original quote. Most are done with 70% IR film that is "almost clear". These films offer 50% reduction in glare,50% heat rejection and 99% UV protection on top of 90% infrared . Without reducing visibility.