In 2005, ITS ran with SSM in MARRS and I thought that actually worked well. As one of the faster ITS cars, I had very few issues lapping SSM cars. In general, they watched their mirrors, and we didn't try stupid moves. Sometimes the traffic hurt me, and sometimes it helped, but that's part of racing. I do know that some of the faster Miata drivers had a problem with some of the slower ITS cars, but I believe that was simply a lack of courtesy by one or two people. Mixed groups can run well together if people are aware of what's going on around them and are willing to play nice.