You may have installed wallpaper but window film installation requires a relationship with a professional installer because installing window tint is an art and a science and requires experience to do it well.
Most professional installers sell only automotive films with lifetime warranty against cracking and peeling and other failure modes of the window films. In addition, professional window tinters know how to protect interior and hidden electronic components from expensive damage.
Another reason to get your car’s windows tinted from a professional is the area where they will apply the window film. The area should be a dust free area in the vehicle’s interior which is clean like a paint booth (something a DIY application is unlikely to find).
Contact a professional window tinter to have them show you these benefits in their store or showroom – if you need help locating someone, check out https://programedge.com/dealers/locate-a-dealer/