These lightweight seats reduce the overall chassis weight of the vehicle by approximately 10 kg. (motor-prime.com)
The rear subframe and rollover hoop are made from steel for a total chassis weight of 454 pounds. (automobilemag.com)
for proof of this look no further than its twin the BRZ which has a front bias spring rate that more closely matches natural frequencies between front and rear based on actual chassis weight distribution. (automotivethinker.com)