They now have sport and super sport listed on the site:
http://www.hrsprings.com/application...ts/4/1686/2015
Sport Spring Front = 1.3 Rear =.80
Super Sport Spring Front = 1.6 Rear = 1.0
This is much different from the M4 springs (the sport is):
Sport Spring Front = 1.3 Rear =1.2
Super Sport Spring Front = 1.6 Rear = 1.0
Looks like this will fix the rear being too low on the M3 versus M4.