cars look cleaner with tint..i hate ppl with brightlights..and the ones with H.I.D's that can't install them right..are even funny..i say rock 35% front and 5% all around the rear..thats what i did..I wouldn't put any, cars look cleaner without tint...
As said somewhere above, your interior color will make tint look darker or lighter than what it is.
This is 20% with almost all black interior.