Loads of room on a series to route the pipe, I split it and brought it up from the outside each side to the arms tied it with cable ties.
Vehicle wiring product do the washer unit, if you can get it use rubber hose not plastic, it seems to last longer. The other bits you can pick up locally, splitter hose etc.
If you want to have heated washer water try coiling the washer hose round the heater pipe a few times