May want to find a smart friend with an engineering background (pref mech engineering) who is also a sportscar enthusiast to help assess crash structures/systems of 996TTS/997S vs 360/612/430, esp evaluating crumple zone design, fuel tank placement, side door reinforcements, airbags (side/head, size of bags, etc.), torsional rigidity, interior compartment safety engineering, etc etc. Draw your own conclusions and place your bets appropriately.
If all else fails, rationalize your decision by arguing some combination of: there's insufficent crash data to draw scientific conclusions; the US govt would never allow an unsafe car to be sold in US; unsafe drivers kill more than unsafe cars; and, finally, we're all going to die of something....so whatever....