Thanks for everyone's comments so far, safety is one of those subjects that often gets overlooked when we modify/race our cars.
We don't bat an eyelid at blowing $17k on an engine and fuel system but go out racing in $150 helmets.
Nauli & Jacob I would love to run harnesses but they are a no no with oem seats. I have already broken an oem seat four years ago in a low speed crash at Mc's. My car still gets used for school pick ups/drop offs etc so too much pissing about swapping things in and out. The only way I can see it working is to have a harness bar bolted in across the rear towers, like how Russ set his bugeye up.
That way the rear seats would not be interfered with where my kids sit in there own RACECAR backseatdriver seats!
I tried purchasing an AGI harness bar for this purpose a few years ago and it was a disaster of epic proportion as the bar did not come close to fitting correctly.
AAAAAAnyway these two helmets are where I am at currently.
ST5GTN COMPOSITE - stilo
ST5FN CARBON - stilo
