I've seen retractable sun shades on vehicles, usually deployed on the rear window, but also the rear side windows. Perhaps that's a solution for you.
Personally, I don't care for tinting. Too hard to see out at night. If I lived in a hotter climate or did extended visits to Hell, I could see the value in tinting.
I think South Florida might qualify. I have 5% on everything but the windshield. It serves three purposes: it keeps the interior cooler on hot days, it keeps prying eyes out, and reduces solar damage to the interior. Leather interiors definitely last longer when they're not exposed to UV.
I have strong feelings on the legality of limo tint, I think its a crock of **** the police can tint their cruisers, but us lowly civilians have use a neutered version. I know officer safety can be an issue, but the few times I've been stopped the officer asked me to roll my back window down so he could have a clear view of the interior of my truck. I should add, in FL its perfectly ok to put 5% tint on the side windows behind the B pillar. This goes to show there are procedures the police could use to circumvent the danger tint creates for officers. Washington state has different laws than the rest of the nation regarding headlights, due to their rainy conditions, so I don't see why we couldn't have something similar in the southern states.
Just an FYI, there is now a transparent tint that blocks almost all UV light. That might be useful for people who don't want to go any darker than their factory tint.