Door loom T27a plug pinning on car side

Hi

I am looking to retrofit aftermarket blind spot detection lights in the wing mirrors and researching how to get two wires out to the door. Many moons ago when adding speakers to the doors of my mk3 golf, I drilled a hole through both sides of the plug to create a hole to thread a cable through. I am keen to do things with a bit more finesse.

There seems to be plenty of availability for the door side of the plug e.g. https://www.amazon.co.uk/Wiring-Harness-Replacement-1K0937702C-1K0959843C/dp/B0F7R9DHXW or even indivual wires with the pins on, but I cant seem to find anything for the car side of the plug.

Or is the car side full of wires and I would just need to cut one that is unused currently to tap in to?

Thanks