Punto (Mk2/2b) Punto Mk2: Timed ignition wiring for HU

I adopted my Punto Mk2 3 months ago and one of the first thing that drove me nuts was that I have to manually turn on and off the head unit every time. There are guides out there for that, but this one is a bit different.

In this guide i will cover a "hidden" functionality of the punto, that i discovered accidentally but it turned out to be very useful, baseline is you can turn the HU on by switching the key to ACC position but if you remove the key or turn it to OFF the HU remains on for a few minutes or shuts off when you open the door.
Sound like a great feature, right?

There are two reasons for this, one is because of the imobiliser (a window is implemented in case it loses communication with the chip inside the key) and the other one is to let the driver close the windows after removing the key.