Do you have an extra plip or is it just the normal red key. IMHO, the auto closing feature was not available on cars before the facelift, I'm even unsure the facelift cars got it. Also, it seems that only some of the higher specced 147 had this feature because it needed some window seals with built in pressure sensors
Also, the cabin monitoring system usually requires two sensors. On most cars they're fitted on top of the A pillars facing backwards, or on the B pillar, one facing forward the other one facing backwards. It's really strange that. It could be interesting to yank out that centre vent and see if any wires or sensors would show up. Perhaps following the wire could lead you to an aftermarket alarm
I have an aftermarket alarm which I wired into the existing remote control circuit, meaning I dont need an extra plip, just the remote that's allready built into the (red) key.
I haven't got any pictures of the navigation thingy. I used to, but must have deleted them from my hard drive. I'll try take a photo later on, or sometime tomorrow. I'd rather do it when there not a lot a people around. One does come across a bit anal, taking pictures of ones car in the middle of the afternoon