The standard of driving in The States is very poor compared to here. Despite the big wide and mainly straight roads Americans still manage to have around 30k deaths each year on their roads. There's also a difference in their laws, using mobile phones, even texting is O.K in some States plus the fact that seat belt laws are quite lax and drink driving is sadly very common. In many places there are no safety checks done, similar to our MOT, just an emission test I understand When it comes to the 350Z being so dangerous in The States, one of the problems is that many are in the hands of young inexperienced drivers, they are incredibly cheap over there. I read a very sad thread on one of The U.S forums where the mother of a young Zed fatality (in his late teens I believe) was convinced that the car was at fault, saying he was a very safe driver despite the evidence that he'd lost control at very high speed on a dead straight road. I think one of the most telling figures was the very high percentage of 350Z fatalities were actually single crash victims which gives me a clue to how they were being driven at the time.
BTW, I have been driving since 1966 and although I have seen the aftermath of many very serious accidents in The U.K, I have never actually witnessed anything more serious than a few minor bumps. In The States I have seen 3 big accidents actually happen, including a hit and run and a car being launched off a verge, flying about 100 feet through the air and slamming into a barrier, scary stuff.
Pete