Alright well I ran a search, found a bit of interesting information and the general concensus seemed to be that overall the WRX doesn't offer too much as far as a sound system goes. This probably could have gone in the 'car purchasing forum' but I think it fits here too.
I'm just curious as to what kind of upgrades you all have made in the under $300/350 range. I don't really know the first thing about sound systems even though I've done a little bit of reading on them. It seems like overall a headunit (I'm guessing that's the deck, right?) is the most effective upgrade. Does anyone know what installations run?