I just wanted to add my input to this thread. My STi's steering wheel is also not aligned properly. Easy way to test:
1. Drive up a small incline when no one is around.
2. Roll backwards straight down the hill.
3. What does the steering wheel do?
In my case it confirmed that it was off to the left, i.e. the wheel is turned to the left when I am going straight. It just doesn't annoy me enough to fix it at this point.
Definitely a good idea though to give the shop in question specifics and request a print-out at the end.