^^^ If they're like my dealership you won't have to show them this thread. My service center was actually very accommodating; on all 5 times I brought it in for this problem.
The last time was after my entire frame was replaced. It started squeaking almost immediately after (although the seat is nice and stiff now). I had only a few hundred miles left on the factory warranty, but they still looked at it again and shuttled me to work free of charge. The only thing they could do was lube it again (making my car reek like oil for a week).
After replacing the frame, there really isn't anything they can do short of swapping the entire seat (but replacing the frame is almost like doing that anyway). The service manager was very apologetic, and we had a conversation about how I've heard online about this being an issue, about people having the issue after only 5,000 miles, etc. and he listened attentively, sort of shaking his head in disappointment.
It's a design flaw with how the seat is put together apparently. Some people are shaped just so and weigh the right amount in the right (or wrong) places to make it happen relatively consistently (btw I'm 6'2" and 180 lbs, so it's not an overweight issue, probably more of a shape and distribution issue). For example, some of the techs in the shop could make it happen almost on command, while others never heard it at all, no matter how hard they tried.
You may get lucky and a new frame will help, but my guess is it will be temporary. I've been thinking about writing SOA a letter in how I love their cars, but how disappointed I am with their interior quality, and that if they don't fix this issue I may think twice about buying a sub again (it's incredible irritating and embarrassing, though in the big picture it is a small issue and I probably shouldn't let it bother me so much).