Start with fitting the mounting bracket for the washer bottle so you can do a test run with the wiring for the washer bottle motor and see which route fits. Then remove the bottle, leaving the plate in place, to fit the fuel filler cover.
The washer bottle is not in the manual. It used to be under the bonnet against the passenger footwell, but got moved into the boot, and it seems the manual wasn´t updated.
Locate the mounting bracket, mine was with the misc bag which contained various parts for the engine plumbing. Open up the hole in the middle of the mounting bracket to 5mm. Remove the relevant bolt holding the rear wing, and fit the bracket before refitting the bracket.
Now place the bottle into the bracket, and see how much slack you have in the cable to power the motor. This will decide if you route this cable out the front or the side of the fuel filler cover.
Fuel filler cover.
Like a lot of stuff, this probably won´t fit into position straight out of the box – offer it up first, but you may need to trim approx. 5-10mm off the top using a dremel. Dry fit IVA trim around the whole cover and see if it fits into place. The cover screws into the boot floor, I opted to screw in to the boot floor and put the carpet on top, so when you take measurements do it with or without carpet as appropriate!
Two items need to come through holes that you will drill in the cover – the clear tubing that transports the washer fluid for the wipers, and the wiring which controls the motor (the black rubber thing on the washer bottle) which pushes washer fluid down that tubing. Be careful here, my wiring was too short to go out the front of the cover and still reach, so do a dry fit first and route as appropriate.
Both wiring and tubing need a grommet, so drill the holes using a 10mm drill bit, but only fit the grommet to the washer fluid tubing hole for now. As usual I used my third party grommets and used pin punches to manipulate grommets into place.
The wiring hole doesn´t have a grommet fitted yet, this is to make the next step easier. Place the cover in the boot, and push the tubing through the relevant hole (in my case at the front). If this is tough, a little bit of Holt´s spray can lubricate it. Now using the terminal extraction tool, make a note of the orientation – which wire plugs into which terminal, and take the plastic plug off the end of the electrical wires which power the washer fluid pump. Then push the wires through the hole in the cover for the wiring, before placing a grommet over the end, as in below picture :
Now push the grommet into position using a pin punch, then reattach the plastic plug to the terminals. Move the fuel filler cover into place, and mark the holes on the boot floor, and drill out with a 3.5mm drill bit. Be very careful not to push too deep – the fuel tank is below! Then screw down with two self tapping screws.
Finally, put the carpet down (you may need to trim around the cover if you are following this approach) and then put the washer bottle into the bracket. Trim the washer fluid tubing to length, leaving a little spare, before hooking up and plugging in the bottle.
The white widget in the plastic washer fluid tubing between the motor and the fuel filler cover is to prevent the fluid seeping forward when braking/jacking car up I believe.
As with the tunnel side carpets, smooth this out ahead of time and weigh it down with a few heavy books to get it flat. I didn´t glue the boot carpet down in the end. If it does need gluing this is easy to do later, but for now I´d rather have flexibility. As the car is R pack, there is only bottom boot covering. The S Pack includes carpet for the sides of the boot.