Bras: Paint, Door Edge, and Headlight / Foglight Protection

How are these gizmos fastened to the car? Straps? or are they glued on? Can they be removed easily should one want to? I think Mylar has a tendency to become brittle and discolor over time.
Humu

 

I looked up the website posted here, for the clear mylars. They seem pretty high tech and clean looking, but I would imagine you'd have to have them professionally installed otherwise they'd look really bad. To properly do the front end of my Prius, however, would cost me about 500 bucks, NOT including installation. I'm pretty handy with tools, but looking at the pattern for the grill and lower hood, and imagining this in mylar trying to fold over on itself while I squeegied the thing into place....while trying to avoid wrinkles, etc, etc. You get the picture. It would be like trying to put pants on a big fish.
I don't doubt they protect your front end, but, hey, I've never had anything like these things on any of my cars and I've never had a headlight broken by passing trucks or my hood dinged. Seems like too much money to me.
Bob