When I bought my tint, I had 3 choices for the shade darkness......light (35%), medium (20%) & dark (5% or 'limo tint'). I factored in the colour of the interior, the sun fading it over time (they say it's fade resistand, but were talking about the sun here) and of corse the appearance. I went with the medium shade as it looked the best & was not a problem seeing out driving at night time, which the limo or 5% shade is. I put the same shade on all the windows (except windshield of course) & used a Llumar 'metalizied' & scratch resistant type of tint. B)