I have a very light tint (vinyl pre cut) that I like.
Got stopped recently when I moved to FL and the cop just wanted to see the engine as his wife has a 2004 3.0 Z (and no he is not on the forum though I did tell him to check it out).
I asked him about the window tints and taillights as I was new to Broward county and he said he would be shocked if someone stopped me for that as they were so light.
I personally would not go any darker