In Euro NCAP testing, the Fiat 500 has a 3 star rating[1], and the Smart fortwo has a 4 star rating[2]. So while not among the safest cars on the market, they are certainly not the deathtraps you suggest. The Smart in particular offers very respectable occupant protection for its size.
That's reassuring
> for its size.
That's not. Passengers risk rises with the size of the incoming car, not the car they are riding in.
There are much larger cars that perform worse on occupant protection tests than the Smart does. For example, the Jeep Wrangler:
“Basically die instantly” does anyone actually believe that?
If an opposing car pushes a part of your car into your body, that's like you being hit by a car while standing in front of a wall. Once the pressure wave hits your body, where is it going to go? You can't be "thrown clear" through the back of your own car.