i don't know. i do know that california has more cars than any other state by a large margin. i also know that in a 60 mile radius of where i am now, i can think of 9 subaru dealers, and they are all selling pretty well right now. this isn't in the "midwest" or "southeast", this is in a small area of southern california.
it would be interesting to know the percentages of sales per region. you'd think that someone would be able to post that info by now.
and yes, i'm pretty sure that irvine subaru has sold close to 2000 wrxs, which is close to 100 per month. there are a LOT of wrxs here. we have meets that are announced a week before they happen and 60 imprezas show up just from local people. and most of them are modded. it's like a little impreza show. it's fun.