i spend all day in the shop trying to find this speed wire, so i figure i save someone some time, cause Crutchfield will point you to the wrong wire. the wire is behind the front passanger side wheel, there is only few i am not sure which one it is.... but dont try to open your instrument cluster like crutchfield will tell you, by the time the speed gets there its already in digital form...thats why you have to get it behind the wheel.

Not surprising you'd have to go to a wheel speed sensor in a vw.