Even standard window tint does a massive job in keeping heat out of a car interior. I've had cars with both factory green tint and (illegal in CA) full car tint, and the full car tint does a much better job than factory tint alone.
The tint I run on the Focus sedan has been on since 2003 and I've never been stopped for it. It's 5% (limo) in the rear window, 20% (dark) on the rear door windows , and 35% (medium) on the front door windows. In conjunction with cracked door windows when parked, the car is usually quite comfortable to enter during summer, even when I can't come up with shade to park under.
I wish they'd change the law in CA so that you can have tint, but are obliged to roll down the windows when you are stopped for a traffic violation. I think that would alleviate the concerns of law enforcement officers for their safety.
2011 Blue Ocean SL with 77,000 miles
2015 pack on 12/30/15
Bridgestone Ecopia 422+ tires
L1 EVSE upgrade
Superbright LED lighting
2013 sun visors
GT-R map lamp lenses
Altima illuminated door switches