(A head-on crash at 60 MPH is like hitting a brick wall at 120 MPH.)
This is not true at all. The amount of energy is the same as hitting a brick wall at 120 mph, but the energy is spread over both cars. So the end result is actually the same as hitting a brick wall at 60 mph.
The Mythbusters got this wrong once and were buried with people correcting them, so they tested it and it turned out the viewers were right.