Interesting question. The best way to see is to goto a place that tints, and look around. Most cars, especially non-entry level cars come with factory tints, so those compounded onto 35%s can be fairly dark. From a personal preference, I would not recommend going darker, its actually a danger at night as it does become hard to see out of. Aesthetically, 35% is also quite nice, as it doesnt look wannabe gangster black.