John, Virginia enacted rather strict laws about window tinting a number of years back (after one too many cops were shot during traffic stops). Laws apply to all windows and govern light visibility out as well as visibility in. In Virginia Beach, out of town visitors usually just get a warning, but if you have VA plates they will fine you heavy. Just a FYI.

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Doug, I don't know of any state that cares one way or another about how
dark the tint is provided that the front window is clear, and the driver
and passenger windows allow sufficient light to meet the state standards
for light transmission on those windows. What is required on those two
windows varies a little from state to state but not much.
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