I'm surprised no one else pointed this out. Assuming the cars were roughly equal in mass, your empeg actually only survived a crash at 20 MPH.

From the frame of reference of the empeg, it was traveling at 20 MPH, then at 0, so it had a net change of 20 MPH. The only importance of the other car's velocity is its contribution to the momentum of the other vehicle. (We have assumed that the crash was head-on.) If the other car was going say, twice as fast (and they massed equally), then your car would have been forced backwards at about one third the speed it was originally travelling. Your empeg in this case would have expirienced a net change of 26.6 MPH as opposed to 20. Same sort of effect if the other car were more massive than yours.