How "late" of a VW 1.8t?

Most VWs use Bosch alternators with internal field circuitry; ergo not even with the sheisrocket would there be a field wire to bisect. In that case, I'd recommend bisecting the wire from the battery to the starter with the main cut off circuit, then bisecting the main ignition wire through the secondary normally open circuit of the switch ("Z or 2" in the diagram on page one.)

For the 1984 Scirocco, the secondary wire to bisect would be the "15" or "switch on" circuit that supplies power to the rest of the car, a 16-gauge black wire coming off the ignition switch. Cut that wire and the car dies.

GA