Oh yeah, you can also rob stores. Probably not necessary but fun too do with your Jason mask on.
Go up to a store clerk that usually stands behind the counter, hold down the auto aim button with your pistol drawn out (cause it just looks fucking cool
). You will start noticing a pile of money appearing near you or your money count increasing. Hold it for more money, but the amount is limited and the cops wants you dead and deader the longer you stay robbing the store man.
And that apache is called Brown Thunder i think... I've never gotten all 100 secret packages (sold before i knew about this), but i heard if you do get em all, the apache in the army base will ALWAYS be there and the soldiers occupying that area will not turn hostile. Or may be the thing gets delivered to your mansion :/ not sure