Eibach # 0700.250.0325 as used in NA6 Spec Miata rear
Like this https://www.summitracing.com/parts/eib-07002500325
Two for $80 shipped
2009 MX-5 STR and track toy
2003 Z06 -- Not a Miata, but 3200# and 400 RWHP is fun
OTM -- 2012 Sierra, 2016 Impala (Appliances)