In the case of the Clubby wagon, it's got almost the exact same performance as the sedan - and you already know how much arse they kick through the corners stock.* With a set of uprated springs that emulate what an FE3 option would be, it'll outhandle 'pretty much everything short of an Elise.'
I don't know as much about the AMG or BMW wagons, but don't let misconceptions make you think that an Audi, BMW, HSV, or BMW wagon ain't a BEAST (some of them might not be, but shit, I bet they are. Audi especially).
*Holden & HSV aren't using the long wheel base Statesman platform for the wagons anymore. The wagons are no different from the sedans except the addition of about 100kg and a change in aerodynamics** due to the changed rear shape. So there has been a biit of a sacrifice to storage capacity there, but you get sedan performance for it.
**Maybe not for the worst, that wagon has a bit of a Kammback look happening almost, and the rear tailgate hinges in such a way that it doesnt really come out further than the rear bumper ass you lift it. Clever.
And some fucken righteous rims:
http://www.blogsmithmedia.com/www.autoblog.com/media/2008/09/r8_tourer2.jpg

As for the Caddy wagon, FUCK Bob Lutz with his 'We aren't exporting the Holden Sportwagon range to the US because wagons just aren't fashionable' shit, when he just goes and then creates this:
http://www.gminsidenews.com/forums/gallery/data/570/medium/ctw2.jpg
While postin pics, there's some new SS rims comin out, look a little Ferrari inspired (of course, they're not) in this pic though:
