Well folks, here is an update from MUC.
I could not confirm the 911 ahead of time, as I mentioned in my previous post, either via the website or phone. Upon landing in FRA I asked the PA in the FCT to book it for me. She was able to do so but only for the three hours (not for the full four days that I wanted). I was told that I could do 24 hours for Euro311 but I would have to return the car to Frankfurt not MUC. No thank you!
I also tried to book through Avis directly and they said "nothing available".
Called AMEX, booked it - DONE!
I am now enjoying a black-on-black Carerra 4 GTS in the alps for my entire trip! The total cost including insurance is $347/day which is a deal for a car of this calibre. I have paid twice as much to rent supercars in US cities.
As an aside, when I have rented through the LH/Porsche deal in the past, I was given a 911 Carrera 4, 911 Carrera, 911 Carrera 4S, but never a 911 Carerra 4 GTS. The GTS is an amazing vehicle. I have never driven a GT3 but this GTS far surpasses any other supercar that I have rented or owned. I am hooked
TFD (trying to keep the rubber on the road)