I had it on my Tundra for 10 years. It was finally starting to turn yellow. My truck was white so it showed the age more that a darker color probably would.
I installed it myself, it was not too hard. Basically you spray soapy water over everything, the vehicle, the back of the material and your hands. This allows you to position the material and then you squeegee all the water from beneath and the adhesive sticks it down. Doing the bumper on our cars will probably be a handful. Better have two people and make sure everything it clean. If you get any contaminants on the back side the film it is ruined.
I have ordered film for my headlamps for some extra UV protection. http://www.etrailer.com/Lamp-Guards/...eid=2012992498
With the way the tops are exposed to the sun I think they will start to turn. If you buy a kit (I think that may be the same place I got mine) it may include headlamp film as well.