I always have my car windows (driver and passenger) tinted to match the back windows. It helps considerably in blocking the intensity of the heat radiating into the car. Washington has restrictions as to how dark the tint can be but they don't substantially enforce it. In the southwest nearly all the cars have added tint to their windows to block the UV and heat allowed into the car. Our tinting guy told me last time I was there that some people that have bright light sensitive eyes have the front windshield tinted as well, so apparently the curvature of the glass isn't a problem. This would be a good alternative to the exterior shades or in addition to.