1993 polo wire and plug identification

I am in the process of tidying up my radio wiring harness.  It's been butchered over the years and now is a lot tidier.

I can't identify one wire.  It's blue and white in colour and is connected to pin 10 of a 12 pin plug (with the rest of the radio power feeds).  Is this the illumination feed for the car radio?  If so then it should be connected to the orange wire of the ISO connector?

There is also an unconnected  small brown plug with a blue/white wire buried next to the 12 pin plug. Is this the illumination feed for an unconnected switch? (say some optional extra like heated front seats)