RS Components Australia
25 Pavesi St
Smithfield NSW 2164
Ph 1300656636
It's called pvc tubing, I bought a roll of 8mm a year or two back for some rewiring I did on my RM. It's the stuff all the wiring is enclosed in ie stator to coil etc. Comes in different diameters, 8 or 10mm will do most applications.
Can't remember the cost, but you do have to buy it by the roll of about 30m. May have cost $60 I think.