[CatsEyes]

This is kind of random, but it may just possibly help.

If I leave my turning indicator on when I turn off the ignition, the front parking light (and I think rear light too) go on and stay on on the side that the turning indicator would have been on. (If that makes sense.)

I've no idea if this is a wiring issue in my car, or some weird Porsche feature. I never thought about it much, since it otherwise affects nothing.

But it does suggest the wiring for the front parking lights and rear lights must be either connected to, or capable of getting messed up with, the turn indicators.

That would possibly explain your most recent symptoms.

I doubt this will help, but just in case...