Hi Mike.
All the fans use four brushes, 1.8 2.0 2.5 & diesel, not all the late cars came out of the factory with 2 speed units, therefore your (It should also be noted that when the resistor fans came out, the all variations were fitted with 2 speed units.) will not be true I have seen 2004, 54, 05, 55, and 1 2006 with a four wire 3 speed fan, all on diesel cars.
I will be tacking a diesel fan off today, which I will open up at a later today or possibly tomorrow.
This thread will help the member have all the information to work out which fan they may have on their car nice idea
Arctic.