For clarity, in which country is your American Express card issued?
it is us based chase which i believe has "luxury" exclusions as well - not sure if jag is explicitely spelled out..
i also wonder if booking a regular car and getting involuntarily upgraded vs booking a specialty luxury rare wharever car makes a diffetence...
doesnt make much sense overall - jag can be 30-40k and much cheaper than many card hertz offers not excluded