I really wish material with the attributes I spoke of existed.
3m Scotchcal is the material used by Invica-Shield, Xpel, Stongard, etc. To the best of my understanding,quality is determined by how well the pieces that fit over the parts of the car are cut. If you investigate each one, you'll see some of the pieces for the hood, front, etc are not the same shape from brand name to brand name. The best fitting ones, Armorglove is mentioned here a lot, are probably the most costly.
I have the Xpel headlight guards still sitting in my trunk. I have a friend who is very good at this kind of stuff to help but he had surgery on his hand so still waitng until he can help me out. I'm not confident enough with my own ability to install because if you mess up the whole piece is ruined.
I think Eastwoodco.com has plain sheets of Scotchcal. One could manipulate to place in spots like under the doors, around the door edges, etc.
One thought I had is if Scotchcal placed on the bottom of the front bumber of some lower-to-the -ground cars, Chrysler Sebring comes to mind, would save the paint if it ever scraped against a sidewalk or dip in the pavement. The Scotchcal could be cut to shape and placed on the underside of the car, it would probably be ripped up but the paint would be saved I hope.
Excellent project for someone real good with their hands.