[DFWX]

Rambling on...
Do I think a new version "928" should be released?
No, the 928 has been effectively killed as a status car and could not bring the price.
I do believe it a terrible mistake for Porsche to not rebody the 928 in 1988 or with the release of the 5.4 360 hp 32 valve, 4 cam motor. They merely would have needed flatten the roofline a bit, more fender flair and rise to give a bit of hood drop down look with a tad of a slant nose, added rocker panels as a ground effects appearance, a kicked up tail with different wing, and make the interior less lavish and more techno.

I have no idea how what Porsche should do. With even Porsche enthusiasts going after the Cayenne, Porsche is getting into a corner in terms of design and marketing versitility - which time to time in the auto industry now means survivability. Issuing all-new models is extremely risky given the billon dollar set up costs...
Not given the Cayenne a "9" number was a mistake. Calling the Boxster an Boxster made sense as it focused upon a recognized engine design (Boxer motor).
It would have been wiser marketing to call it something such as the
957 SV (not being trapped by the "SUV" perception), with a "Cayenne" edition, thus allowing a new name for the edition if Cayenne did not work and offering more variety within the same model by having different model names, while the same number (such as 911 widebody, 911 turbo, 911 GT1 etc.) Thus 957 SV, 957 SVT (turbo) and other edition names following as well.
Not many people every heard of a Cayenne and nothing identifies that to Porsche.
Porsche could drop the Cayenne to the ground with a 2+2 GT body in the 3,400 pound range with 450 turbo horsepower for an all wheel drive top end performance road car and numbers that go up against the other 4 wheel drive exotics. Ot they wisely could just bump it up to 5.0 for 500+ hp in an all wheel drive performance road GT.
Would you want a 520 horsepower alloy V-8 Porsche 2+2 all wheel drive
195 mph GT? Bet you would. Even if the motor is up front.
I don't think Porsche made a 948, did it? 9 - like most model Porsche, 4 - for 4 wheel drive and 8 for cylinders. Or Porsche could go bolder and go V-12 with half again the Cayenne motor and again go for "FASTEST PRODUCTION CAR SOLD IN THE USA" with other than a half million dollar car that actually is semi-mass produced.
The 928 gave Porsche parity with Ferrari, Lambo, Aston Martin for a few years and in a model that was not just for the super rich. If I were Porsche, I would make that the goal again. For 3/5th the price of a Ferrari, you could buy a Porsche that is faster and is a 2+2 fastback.