I reckon Mike is the first person I've ever heard mention "American cars" and "oversteer" in the same breath. Most people call them boats for the simple reason they tend not to turn immediately when you tell them to
I've not noticed any major physics changes between the two versions, though I guess the tyre flex might change some of it. It is possible that your 'Ring example was down to a slightly different track model as well as any minor physics changes.
There was a stock Cobra championship in FM2, wasn't there? I had to hire the AI to do it because I found driving the thing so frustrating. Had a similar issue with the old Ford GT40