Ok, this happened last summer too but I forgot about it.
Today, I noticed my phone didn't ring or are playing any sound. Digging a bit into it I realized it's connected to my Spark's bluetooth. Weird, I thought, it's down in the garage right now with "ignition" off. I went into the garage and note that the car is fully charged but plugged in. However, I do notice a constant fan sound like the thermo-regulation is still trying to cool it down. Once I unplugged the charger, the car's bluetooth turned off.
Now, I'm quite sure this is a bug in the programming. When trying to charge in hotter temperature (80+ deg?), the bettery cooling turns on but it woudn't turn off when charging stops and another side effect is that the MyLink bluetooth also stayed on.
Am I the only one seeing this?