I changed out the factory fill oil at 3260km, ideally I'd have done it a bit sooner, but you know...
When I removed the undertray, I was able to have a bit of a poke around under there.
First thing I spotted was the in line electric water pump to cool the turbo after shut down (the actual water pump is a variable geometry design). This explains why I can hear a whine much like the Prius inverter pump after shut down:
It seems that this would be a good idea for anyone with a turbo doing much engine off stuff. My Fiat has factory S/S and no such pump!
Electro-Hydraulic Power steer pump. This explains why the steering works with the engine off, but it feels like hydraulic steering:
Could be useful for swaps into bigger vehicles where the Toyota MR2 pump might be insufficient. I didn't look into how complex the wiring is, but probably not as simple as the Toyota three wire hook up.