The pump is behind the side panel that is behind the CD changer. You'll see it if you ever need to get at the aerial

Given the location, and the plumbing diagram, this suggests that 2 separate pipes (boot lock and fuel flap) will be traversing the boot space somewhere, ending up in the same area around the fuses. Odd really, presumably they're behind the trim on the boot sill.
(rather different to my earlier assumption :o )

Its so you can enable the secure unlocking or whatever they call it, so that with one click of the fob only the Drivers door and fuel flap are unlocked so theiving scum cant jump in the passenger seat and put a knife to your throat, or something along those lines.....

Then a double click unlocks all the doors......

99% sure they go forwards from the CLP over the wheel arch, splitting for nearside doors, then across the back seat floor towards the drivers side, splitting as required to go into the offside doors and two feeds to come back over the offside rear wheel arch to head to the boot and fuel flap...

The reat seat squab is 2 cross head screws and 5 mins to remove to check....

Thats right, and I think the confusion between the diagram showing what appears to be the nearside door and Ians explanation here can be attributed to the diagram being for a LHD car. It isnt the nearside door and offside fuel flap in the UK, it is the Offside (drivers door) and the fuel flap that unlock on one click, and the remainder on the other click....I always found it quite annoyng however and changed it back to the 'ord fashioned way' where everything unlocks at once....:)

They do mostly, indeed go forwards but the boot lock pipe goes forwards and through the grommets by the nearside hinge and into the boot

So that diagram is probably for a LHD model - fuel filler still on the right?
It will presumably still need 2 pipes into the offside rear area.

I disabled the secure unlocking on mine as it's rarely driven alone and is a PITA otherwise. (Though it's enabled on the Focus - different pattern of use)

Edit: beaten to it by others. :o

Where did this come from? Is it EKTA/ElsaWin/something else? And where can I get it?

The pipe deffo runs on the N/S of the rear seats as i seen when i had mine out the other day

I normally get them from ETKA but i wasnt at the right computer when I got this one so I used VAGcat -
http://www.vagcat.com/epc/
but you will need to go to www.vagcat.com first and register as the electronic parts catalogue part of the site asks for you to be signed in.
The other thing to remember is that its not right up to date like ETKA but its generally fine for our older models +++