On window-tinting to avoid needing curtains for privacy, one might want to check those windows at night, with a light on inside. While tinting is designed to see out in the daylight, but not in, the reverse is true at night -- it might be harder to see out the windows at night, but looking in, even by holding a flashlight to the window, you can probably see in, as long as there is more light inside than outside. I'll use curtains and be happy with the "privacy" tinting that came with the vehicle most of the time. I had reflective tinting on the windows on my old Econoline window van, and in daylight there was no way anyone could see in -- making whoopee in the back as people walked by did get a little unnerving, though we knew there was no way they could see what was going on inside. They just walked on by, not paying any attention to the van! I don't think you'd get that level of privacy with dark tinting, though 90% might come pretty close.