[David]

I suspect the auto start/stop at least on a Porsche is designed to quit working after awhile. I say that because I left it turned on after my Cayman was broken in (I left it turned off during the break in period and also changed the oil FWIW). After awhile it's function became more and more sporadic so I finally just left it turned off.

One nice thing on the Cayman though is if you stall the engine due to faulty feet action, you push in the clutch and it starts right up without touching the key.

I bought my Cayenne when it was 4 years old and the start/stop never worked so I've always left it turned off.