I don't think you want to get into the collision business with me! The coming back to shape you speak of is for less then 5 miles per hour and they are engineered to bend, as in absorb impact. They do not however, return to shape if unless its a very light impact, and that can be very misleading until the car is torn down to see hidden damage (bent metal, plastic & aluminum)!
I own 2 collision shops, been in the business 35yrs! Please don't parade your ignorance of this subject here!
BTW more and more cars are being made of aluminum, especially high end cars, as well as the new Ford truck!!!
Sorry, but you are displaying an ignorant attitude here.
And yes, of course, Plastic is low speed absorption, not a 30mph head on crash!
Number of years ago, I was in a small hatchback car.
I stopped at a red light.
The women behind me did not stop, she told me a wasp in the car and she was panicking.
BANK.......
My whole car lurched forward, luckily my headrest stopped me from any whiplash injury.
I got out my car, and as I span on the stop to turn around I saw the front her her car Hood, Wing, Lights all smashed up, front of car looked a write-off.
I thought, oh god, bet my car's back end up smashed up real bad. DAM.
Looked at the back of my car, confused....
Looked again, errrrr, WTF
Nothing!
Bent right down and looked and noticed a slight 1" graze in the plastic.
I can only assume the plastic deformed, her front end crumpled taking everything out, and my plastic went back into shape.
I was stunned how strong it was, and never spent a penny on any repair, did not claim off her insurance and nothing to claim. Kept my car for many more years.
Amazing how the plastic took the force and her steel just destroyed itself