I don’t think such a film exists. You either have contravision which is full of little holes, or mirror film which relies on the exterior lighting being brighter than the interior. Sometimes we get asked for the impossible. As Scotty used to say to Kirk "you cannae defeat the laws of physics Captain"
Closest I’ve come to it is a Night & Day perforated vinyl. Contravision and perfect colours do their own variants. White backed product rather than the conventional black. Works quite well, but as the others have said, it has its limitations. Worth getting a sample to see if it suits your clients needs. Good luck [emoji106]