Well I figured I should weigh in here because this is what I do for a living. I should point out I am not an installer, but do commercial window film sales, however I do have quite a bit of knowledge in the subject. To match the rear privacy glass a 20% tint is usually the best match shade wise. Different lines of film will match the color of the privacy glass a little better than others. We are 3M dealers and regularly stock three of their non metalized automotive film. If my memory serves me correct the 3M Color Stable 20 is their best match to our factory glass. Now to clear up items. All window films will block out 99% of UV rays, this does not change with VLT (Visable Light Transmision, aka how much light it lets in). We charge $80 for two fronts, as long as it is not a spectrally selective film, these are films built to block IR rays as well as UV, which gives them dramatic heat rejection without being too dark. These are pricy films, to do a whole 4runner would run about $750 for 3M's Crystaline film. If anyone has any other questions I would be happy to answer them.
Just a little something to think about, you get what you pay for, so that $99-$150 special to tint a whole car is not worth buying. These films will purple, bubble etc, and if they are metalized they could interfere with cell phone, gps and bluetooth signals. It helps to ask questions when getting tint done. All reputable companies should back their work and install films with a lifetime warranty.