Going to look at tints today ... In switzerland you can only tint what's behind the driver (i.e windshield and front sidewindows have to remain clear). Sadly that looks a bit odd with stronger tints, so I'll go for something medium.
I could understand the reasons for the lack of tint up front given the level of sunlight you guys are exposed to in Switzerland & no offence is meant in this comment it is just am assumption on my part.
For us, it varies by state. In Georgia, you can't do anything to the windshield, but the side and rear are ok as long as no more than 70% of light is blocked. That's pretty dark.
The problem people sometimes run into is that neighboring states might have different laws, and you can still get ticketed for it even if you're just passing thru..