I have driven my Nismo over 130 mph on track and it was solid as a rock. More so than any Porsche I have driven. The 370z has fairly long wheelbase compared to other sports cars which contributes to it's high speed stability. Porsche Cayman has wheelbase 5 inches shorter and 997 has even shorter wheelbase that is 8 inches less than the 370.
I'd be very concern about improper alignment or incorrect tire pressures if anyone feels intability in a Nismo. These cars are rock solid at high speeds if alignment and tire pressures are correct. Are the shipping spacers removed from your front springs?
