Well, I know the salesman told me to "let it all out" so I'm sure it had received many of those "all out's"...which scared me. Glad to hear the people who work there do the same stuff. lol
2009 WRX engine failure VIN/build date owner list - NASIOC
I think if your build date is after July, your good to go. If you are finding a 2009 for sale today, i'd be shocked if it had a build date before August.
Factory subwoofer helps. As I am sure you have read, even the sound system in the premium is not the best. However, I'm not an expect when it comes to sound so average sound is fine for me. The subwoofer adds enough volume and bass that I don't feel like I need to go out and spent the $$$ on an aftermarket system. I know there are a bunch of other people who couldn't stand one day w/ the stock system. However, if I had to do it again, I'd spend the extra few bucks for the subwoofer. It's definately something you should hear before you buy though. B/c if its not enough for you, your gonna be upset you spent the $ on an so so/average subwoofer. Ya know?