I have many pics of Turbos and the centre v right side exhaust exit is completely up in the air.
ie #298, 352, 583, 633, 895, 971 and 1365 are all right side
#386, 497, 634, 772, 1431 are all centre exit.
It could be that some cars had new lower rear valances fitted, but, this many???
The Blue parts book shows a part # number change for the rear Turbo exhaust section at 4291212, but what that change was I do not know.
As for non-USA '02s, they retained the right side exit exhaust (except the Touring, which was always left exit, & Turbo).