Some research is being done on the idea of instantaneously filling the entire inside of the car with a transparent, gelatinous fluid that would "imprison" the occupants in the car like bits of fruit in a jello salad. Biggest problem so far is that the occupants cannot breathe in this configuration, so the fluid would need to be evacuated seconds after the impact, along with, probably, earings, sunglasses and other loose items. Also a problem is that the stuff stains fabrics and would thus not be acceptable in parts of Los Angeles, San Francisco, New York or other clothes conscious urban areas. Given the tenuous future of "isotropic gelatinous fluid dispersal", or "IGFD", I opted for side air bags in my Prius. Nice to read that my choice was vindicated by actual testing.
Bob

"Whiplash protection was also rated "Marginal" because of the seat design."


Could this be improved by an improved, maybe retrofitable, headrest design?