As you can see not much has changed in 10 years, beyond 2.0L -> 2.5L of course there are some differences with the sti and wrx (bigger turbo, injectors, and some others). As you can see I had some battery issues recently, turned out the connector next to the red boot on the alternator had some rust on the center terminal. I fixed the old 90amp, but found a 110amp newer alternator for cheap. In my search I've seen some even bigger alternators but they cost a lot more.