Just to advise OP of a couple of other 916 'quirks'. Fuel flap will only open with ignition switched off, In the glove box there is a button that opens the boot which also only works with the ignition off. If you have a Spider with a manual hood then the release buttons will only activate with ignition off. As mentioned before, if there is failure of the fuel flap solenoid then there is a red 'string' in the boot. This will only work to open the flap. If the flap does not close then it needs a new solenoid. Excessive movement of both driver and passenger seats may result in the airbag light symbol becoming permanently illuminated on the dash and then needing to be cancelled by a garage/dealer or home diagnostic software. Also if new to 916 ownership do not attempt to try and lift wipers when cleaning front screen as the tolerance will only allow for about 10mm off the glass before the arms snag of the rear edge of the bonnet.
Hope this is helpful and not too obvious, enjoy the car.