You don't really need a dealership for that stuff, though.
edit: just to elaborate: Subaru needs to modify how they treat their dealers or something. I've never heard of dealers selling other cars to go so far out of their way to piss off their customers! As far as warranty work goes I've seen dealers come across certain things where they've had to tell their customer "erm....I'm really sorry, but we have to bring repairs like this to the attention of the manufacturer rep and he's gonna balk at reimbursing us for it because of XYZ". But some Subaru dealers seem enjoy telling the customer they won't do the work. I've even heard of dealers denying coverage only for Subaru to come back and say "oh yeah, we'll cover that" when the customer complains.
So what I'm saying is that most dealerships (SMART dealerships - you have to be a complete idiot to willfully piss off a customer if you don't have to) will look the other way to keep you happy and coming in to give them your money, but I'm sure certain dealers would absolutely love for you to bring the car to them for non-warranty work only to insure you never come back by reporting your mods to SOA.