Installed 3M Crystalline 50 but still feel very hot parked under the sun for 2-4hrs, not sure it is due to dark color car and dark color interior.
A good film will dissipate the heat very fast after you switch on the aircond, and also will reject most heat from outside when you are driving.
After we tint the film, we only can use BTU meter to check the solar heat rejection.
As long as you receive e warranty from 3M Malaysia, high possibility is genuine film.
If you want to 100% confirm, you can go to any 3M authorized dealer to check it.