Is the purpose of the film going to be keeping the car cool in the sun, or making the car *look* cool? If the former, read on. If the latter, consult your local teenagers.

I would get all the windows tinted, including front doors, for better function (and looks). Depending on your desire and state laws, you may be able to put the same darkness film all around. I suggest 50% darkness as a reasonable compromise between keeping the sun out and preserving night visibility. If you live where the sun is really hot, consider going to 35% transmittance (darker). Even darker films are available (5-10%), but these will be very difficult to see out of at night, and are probably illegal except for back windows of limos.

More important than darkness is the quality of the film. The best ones use a metallic (silver, etc.) substrate to *reflect* sunlight. The cheaper ones use tinted dyes, which tend to absorb light and heat, then actually re-radiate heat into the car. The appearance may be the same, but the function is different.

As far as cost, call around to pro shops in your area. Ask about metallic-based films which are spec'd for heat reflection, not absorption. My guess on cost for five windows (actually seven on the 850) will range from $150-300.

Gerald C