California window tint law restricts windshield tint on top 4 inches. Front side windows must have 70% light transmission or more. Back side windows and rear window may have any tint darkness.

Three of the top tint brands are LLumar, 3M, and Hüper Optik. LLumar offers the best sun protection, durability, and legal compliance guaranteed. 3M is an affordable alternative that still gives most of the same benefits. Hüper Optik is a beloved auto tinting brand all over the world with similar specs as 3M.

When vehicles come with a factory tint, it's usually between 15% and 20%. A 5% is the darkest tint you can get, and you can't see through 5% tinted car windows at all. In most states, a 5% tint is illegal. It's most commonly used on the back windows of private cars and limousines.