I've got 35% on the windshield but be prepared for the rainbow effect if you wear polarized shades. I have my front window tinted for well over 10 years. You realize that it not only helps keep the UV rays off of ur entire interior including ur dash, but it keeps the vehicle cooler when in the heat.

 

This is what we call 'trucker tint'. It's 5%

 

I have 5% all around. I have the same question. 50 or 35 the whole windshield.

 

The whole thing? You sure wouldn't want less than 50 at night

 

Sunny here in FL.