Should the sunroof film be applied on the inside or outside?
2 Answers
Automotive sunroof film should be applied on the outside. Here are the relevant details: Film application: Automotive window tinting involves applying a thin film material to the front and rear windshields, side windows, and sunroof of a vehicle. This film is also known as solar film or explosion-proof heat-insulating film. Functions: It primarily blocks ultraviolet rays, reduces heat transmission, and prevents injuries caused by sudden glass shattering (which is why it's called "explosion-proof" in explosion-proof heat-insulating film). Additionally, due to the one-way visibility feature of solar film, it serves to protect personal privacy and minimizes damage to interior items and passengers caused by UV radiation.
I installed a sunroof film on my own car and chose to apply it on the inside. This is because the external environment is too harsh—factors like rain, dust, and scratches from tree branches can quickly damage an externally applied film, making it not cost-effective. Applying it on the inside is much safer, doesn’t affect the sunroof’s opening and closing function, and effectively blocks heat and UV rays. I’ve noticed a significant difference in summer—the cabin stays cool, and the AC doesn’t have to work as hard. During installation, the technician emphasized that the glass must be thoroughly cleaned to avoid bubbles, which can be troublesome. It’s recommended to have it done professionally rather than DIY, as this can extend the film’s lifespan to several years. An externally applied film would be harder to maintain, look dirty, and impair driving visibility. Overall, applying it on the inside is the standard choice—both economical and reliable.
