Ballistic Ping Pong Ball vs. Tennis Ball at 450km/h!

The take away should be that it you're among the 85% of people attempting to occupy the same space as a semi, your vehicle, its safety ratings, and restraint devices don't mean squat. 
Auto manufacturers don't design cars to survive a collision with a semi. Why not? Because the odds of you being in a bad wreck with a semi are negligible, and its pretty much impossible to protect against the energy of hitting a 40 ton truck at high speed. Even if that truck isn't moving. And it doesn't matter if you're in a Fiat 500 or a Ford Excursion, it will be destroyed.