The problem I had were misfires that stayed on the same cylinder even after swapping plugs and coilpacks. It's called an overlay-harness, originally designed for the AWD Golf engine. which is the same as the ATC Audi engine.

It's not too bad of a job, but you'll need to take out:

1. The battery
2. Airbox
3. Wiperblades
4. Panel cover under the wiperblades.

Then you can take the wires off the coilpacks,
off the transmission as well (the new overlay harness comes with a plug that plugs back in the transmission as well as a heatshield for that transmission plug, look at the new harness to see how it plugs in and out).

The trickiest is the get the pins in and out of the plugs, needles work very well. There is supposed to be a special tool for this, but patience and stitching needles work pretty well :)

It'll take you about 3-4 hrs, the tech bulletin helps a lot.

Goodluck!