Confirmed - the connector appears to be X18830 - used for the Telestart receiver for the independent auxiliary heater (Module A128).
The pin connector (X18830) looks like yours up until 09/02, then it was changed to an inline 6-pin.
Until 09/02...
From 09/02...
To be 100% sure, you can check you have +12v on pin #4, ground (chassis) on pin #6, and the voltage disappears when you pull fuse #86 in the trunk panel. (These pin numbers are for the pre-09/02 connector - the pins are +12v on pin #1 and ground on pin #6 on the post-09/02 cars).
Doesn't help your BT issue but it removes this connector from the equation.
