I very much appreciate this info and look forward to hearing more.
I did hear back from Ermis. Insurance was 1% of the value of the car per track day if there is an instructor in the car. Plus a large deductible. So, the quote I received was as follows:
Insured value $85,000
Premium: $850/day with a 50% discount for the second day of a weekend.
Instructor must be in the car
There is a discount for multiple days. If more than 10 then it is $500 per day rather than $850.
However, based on this, it seems very high. Almost high enough to just self insure
Plus, I get nervous dealing with a company via email in France because I can only imagine the pain of filing a claim if something ever did happen!