I don't know how IMSA can keep the GS class as it is, four (4) cars at Mosport! ST still has a good car count though.
The main series top class, prototypes, only has about a hand full. It will be interesting to see what happens to that class next year.
The two series competing with each other is having an adverse effect on IMSA. Many of the teams have moved to the American LeMans & Pirelli World Challenge series . Sort of like the old CART IRL days. Both series seem to get diluted, although ALMS seems to be the stronger of the two.
Looking forward to seeing these on the track. News, also (or at least speculation), re likelihood of MSR continuing to run their P2 car. MSR expected to get Acura NSX GT3 deal (racer.com)
Some more for Road America - was a fun weekend. I barely paid attention to the Minis and CTSC, though Mark Kvamme gets all the attention at Starworks Fisichella's agricultural expedition Late night at the Mazda shop Action Express train with a 1-2 finish Stars and Stripes and Curves