I have for sale 1 set of four (4) Progress Springs for the 2009-2015 NC Miata.
These were purchased from Goodwin
Racing and never mounted, never out of the box.
According to Goodwin Racing these will lower the car 3/4".
Before mounting them I realized my shocks were bad and ultimately went with coilovers.
I am offering them for $150 shipped (US lower 48) to the buyer or for pickup in N East Iowa (52001).