It seems to me that race cars (like Formula 1 and NASCAR) and small GA aircraft (like a Cessna 172 or Piper Cherokee) travel at generally the same speeds, roughly between 70 and 200 mph. Yet, if an accident happens, you appear to be more likely to die in a small plane than a race car.**
I figure this may have to do with some of the safety features of race cars versus the safety features of GA aircraft. The main features being the racing harness and the roll cage. (And also, as Freeman pointed out in a comment, the HANS device and the helmet help quite a lot as well, especially in frontal impacts.)
I know roll cages weight about 80lbs and that they aren't cheap, and I know a safety harness can be difficult to put on and people might not like using them, and I know a HANS device can be cumbersome, as also a helmet can be. But forget all of that for a moment. I'm not asking about why we don't use them from an economic/utility perspective.
What I really want to know is if putting these in a small airplane would be of any benefit to begin with. It's true that they are massively helpful in racing vehicles, but I wonder if the forces racing vehicles face during a crash are markedly different than what you would find in your typical GA crash (e.g., perhaps aircraft accidents happen at less predictable angles, or involve more torsion, etc.). And if perhaps those differences in forces make the use of a roll cage and a safety harness kind of pointless in a small plane because they can't actually help in that kind of accident.
So, would all of these racing safety devices actually make a GA crash more survivable, or does the nature of GA accidents make their use less effective than they are in a race car?
** Try as I might, I couldn't find hard stats on "deaths per accident" in either area. So this is mostly an impression I've gained from reading a lot of NTSB reports and watching a lot of racing. The fact may be debatable, but shouldn't detract from the main question.