Just over a week ago I got a call from my wife that the Boxster was completely dead and the key was stuck in the ignition. The car had been sitting for 5 days, but the battery is fairly new, just over a year old and I use the CTEK battery maintainer during winter storage. The car sat for 5 days over Memorial Day weekend in May and there were absolutely no issues. I tried using the procedure in the manual to open the front compartment lid with no luck. I did not use jumper cables, but a battery charger. I called the dealer and got a recommended towing company.
The next day the tow driver showed up and suggested we try to jump the car. He used a portable battery pack about the size of a briefcase. He plugged the power pack into the cigarette lighter socket and opened the hood using the switch on the floor by the driver's door. He then proceeded to jump the car with the power pack connected directly to the battery.
I drove the car to the dealer without turning the engine off and left it for them to look at. Later that afternoon I got a call from the service department. They could find nothing wrong with the car and completely tested the battery.
I spent the last week using a digital voltmeter looking for any sign of a discharge after the car sat overnight with no luck.
I have concluded there is an intermittent fault in either the car or the battery.
As a solution to this electrical gremlin, I just ordered a Beatit 18000 mAh portable jump starter from Amazon and a cigarette lighter plug adapter. Cost total $75. Welcome to the 21st century. Jumper cables are evidently obsolete.