Sun damage while driving

You still can get sun damage inside some cars. True, it's unlikley that you'll get a sunburn while driving, not even in long road trips, but incremental damage does happen and accummulates over the years.

In most cars, the windshield is treated to filter out UV-A radiation, which accounts for wrinkling, but the side and the rear windows only partially filter out UV-B radiation, which darkens skin. So while you might not darken, you still get wrinkly and all. Boo! (But a few car models actually have better UV-A and UV-B protection).

You can have the windows professionally treated to block out UV rays without tinting or affecting visibility. Incidentally, in California, all new automoblies are required by law to have heat-blocking (either by deflection or absorption) glass by 2012. This makes environmental sense since one will need less energy to cool the car.

p.s. If you can never keep track of which one is UV-A and which one is UV-B, try this menmonic: UV-A causes skin Aging; UV-B causes skin Burning. Both types contribute to cancer.