If you're going for heat reduction but don't necessarily want the blacked-out limo look I highly recommend one of the new(er) ceramic-based tint films. Two of the most common are Llumar Air 80 and 3M Crystalline but there are a number of others. They don't block too much visible
light but still block a lot of heat and 99% UV. Most of these films have a blueish color to them, but if you get all your windows done in it your eyes won't notice the color.
Previously you could get this performance from a metallic window film but with the side effect of blocking a lot of wireless signals. Ceramic has similar if not better heat rejection than metallic but does not block signals.