Hello mate, the rear washer jet is fed from the same washer bottle from under the seats which serves the front washers. My rear wiper didnt work and after investigation i found that the wires had broken in the left hand loom top left of the rear hatch door ( Rubber grommet) After removing the left rear light assembly and the inside left panels i carefully fed a wire coat hanger down the inner panel and attatched new wires to it then pulled through to the top and rejoined the wires carefully taping them up and reassembling it all. Its an easy job to do but just time comsuming and a little fiddly. You need to be patient with it. If you remove the rear hatch door cover you can see all the pipes and wires for the washer and wiper and the heated rear window wire runs down the right hand side of the hatch door.

Hope you get it sorted. Let me know if you have any problems. Regards. Brendan.