I think the 6 wagon is now the best selling of the 6 models. If your looking for a small wagon, check out the saab 9-2x. Its a subaru wrx wagon, with a saab exterior/interior and warranty, for about 19.4k without negotation (employee discount from gm), and as low as 16k with heavy negotation.
In terms of wagons, its the best buy right now. 227 bhp, awd, subaru drivetrain, engine, suspension.