This story is on the forum somewhere, but it was a couple years ago. I was just arriving home from the Palo Duro gathering, when I heard a very loud BANG from the front of my car.
Well, the primary cooling fan, belt driven, was made of plastic, and must have been defective, because it basically disintegrated while spinning quite fast. That sent plastic shrapnel in all directions at very high velocity. One piece put a hole in the radiator, another cut through a group of wires, another killed the alternator, while another took out the AC compressor.
Total damage? $3,500!

And, the car was out of warranty.

After a week or so of negotiating, Audi agreed to pick up $2,500, and I paid the other $1,000.

So, believe me, the damage from those plastic parts could have been MUCH worse.

CD