There is actually no solar film on the market that can provide "nighttime" privacy or deter onlookers from seeing in at night when the interior lights are on. This is not a factor of the quality of the films, but a fact of the laws of physics.
The only films that can achieve that level of security are our Frosted / Opaque films, which as you may know, will also black the visibility from the inside looking out.
The best way to achieve Nighttime Privacy using solar films is by installing a Dual Reflective Film (like Vista) that can provide 100% daytime privacy, then use a drop shade, blinds or drapery for the night privacy purpose. That's the only way to guarantee night privacy and still allow viewing from the inside looking out at the same time.