Is 50% Window Tint Legal?

How to read this: states regulate the light that passes through the whole window — film plus glass. Factory glass already blocks some light, so a 50% film usually meters a few points darker once installed. “At the limit” means the film's rating exactly matches the state minimum: legal on paper, but a roadside meter test can fail it. Verdicts below use each state's verified front-window minimum for sedans (or all vehicles where the law doesn't distinguish).