[Slartibartfast]

I find night time visibility better with tint. Especially the 5% at the rear. It shades the lights of people behind you. I never need to flip the rearview mirror down, and I can still see what's behind me. When you do flip the mirror down (in cars without tint) it's so dark you can't see what's behind you at all.
The tint on the side windows helps when turning out of a parking lot. The oncoming traffic isn't blinding.
30% will still look great on that red!