And do you know what 70% looks like? Basically it is usually factory like that, most put it to 50% - which is technically illegal but let go. And anything under that, usually isn't done "on record" by tint shops.
Stock tails with a smoke finish could be fine - but I'm saying spray on (VHT NightShades
) or tint onto the tails is illegal -- especially if it is too dark to obstruct light output. Basically again, you might get away with a light shade, but anything beyond that is asking for a ticket (which was a $153 fine back in 2007)