A word of advice tristan:
If you are REALLY serious about getting the HANS device to improve safety, ask for advice from specialist engineers e.g. biomedical engineers that actually understand and work on RL conditions with real professional race drivers. The problem with asking fellow racers only is that there's more hearsay, errornous claims and just pure ignorance induced nonsense. If you believed the late Dale Earnhart, the HANS device is a "noose". Look where he is now. He died because the lack of the HANS device to restrain head movement relative to the neck. His head was effectively pulled out of his neck.
The technical term is "basilar skull fracture", a remarkably common phenomena in serious car crashes (in cars with poor or no restraints e.g. airbag to stop excess head movement).
Why were they created in the 1st place? Well, if NASCAR drivers weren't dying from remarkably prevalent basilar skull fractures, no one might have noticed.
To seriously help yourself on this question (to or not to use it), you must seriously consider how they work and what inspired their creation and use in professional racing. So, what causes neck injuries?
Of course, the HANS is useless if say a car flies right over your cockpit and decapitates you, but that's not how most casualties are generated. The real cause of injury is the fact that your seat belts do a great job of stopping your body, but it does nothing to stop head movement. It is the relative head movement between your body and head that causes real injuries. The HANS is effectively a "seat belt" for your head. It is effective as long as it prevents excessive head movement.
And yes, what a lot already say here is true, all the restraints in the universe are useless if your car isn't up to the task of absorbing kinetic energy to prevent to much load transfer to the driver. And higher cockpit side (provided they are strong and tall enough) could help reduce your chances of decapitation.
FYI, I happen to be a biomedical engineer, so I know what I'm talking about when it comes to biomechanics. And no, there's been no real evidence of HANS actually causing injuries and crashes, so don't believe every urban legend you hear. When pigs are born naturally with wings and fly around on their own power, THEN I'll believe seat belts cost lives.
Racing is a dangerous sport, but that leaves no excuse to take safety lightly. Just the opposite. Take it from a guy who used to race around on gravel/mud/soil tracks well defined by rows of trees. And happy AND safe racing, tristan.
