'99 911 Carrera Cigarette Lighter Power Question

[The_Spider]

TLDR: Using lighter to power hands free device, can this be 'switched' instead of always on?

So, I just got my first Porsche, not only did I find a good one, I found a service garage that is capable and skilled at working on it. Needless to say I'm more than thrilled. But I do have a question.

As this is an older vehicle it's not up to date with current audio technology (i.e. My state's hand's free requirement.) I will be replacing the stock radio unit in the future, but have a bluetooth module currently that uses the cigarette lighter and an FM modulator. I'm concerned that the unit stays on when the vehicle is parked and would like to if there is an option or modification I can perform to make the light port switched?