Up for sale is a like new
GTSPEC 2 Point Rear Lower Brace Model # GTS-SUS-1375. It fits all models of the 370z and rates a 9/10 on condition.
$75 shipped to the lower 48 with a tracking number included.
Picture of what the bar looks like installed:
It’s packed up and ready to ship:
Here is a link to a DIY. It's easy to install in 30 minutes or less.