If they have one "STI" coil pack in there, then there's a good chance that another factory one is going bad. They way that things are consitantly manufactured these days (whether it's good or bad), they usually fail about the same time. I would look into changing them all out to see what happens. How did you know that it was a STI coilpack by the way? Is STI printed right on the coil pack? Well, I have to go now and try to fix a POS VW. One thing I will say about Nissans, they are much easier to work on.I bought my spec about 9 months ago and when I bought it it had some issues that I fixed but there are some more. One of them is that I removed the engine cover about a month after I owned the car and I found out that one of my coilpacks is an STI coilpack. I don't know if that is good or bad but out plug works on the STI.
The only thing that I have noticed is that there is a slight miss at about 2000 RPM's. There are other issues with the car so I really havn't looked into that problem yet but I was always curious about the miss. I don't have any codes right now, I had an idle relearn issue and a o2 sensor issue that I fixed when I first got the car.