Yes. I had a Kia Amanti recently -- an upgrade from a C rental -- looking at the car key it was a class H car, which I believe is the same as the Town Car (luxury). I'm basing that on F being full size (Taurus) and G being Grand Marquis (Premium). While Amanti is a nice car and an EXCELLENT upgrade from Intermediate, if I rented a luxury car and got a Kia Amanti I'd be disappointed. I think it's more fair as a G Premium car.
But since I will probably never rent above Premium (again) it won't be my problem

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* Rented and got a TownCar once to show off to relatives in a small little town. It worked so it was worth every penny LOL