OEM 20mm rear sway bar - upgrades 17mm WRX RSB. I believe fitment is for all '02-'07 WRX (note only '02 - early '03 sedans have this stock and it is not an upgrade for those). Currently on an '03 WRX wagon and was a great upgrade with OEM look and fitment. Includes bushings. Used.
The "Will this suspension part fit my car?" thread. - NASIOC
Also I have a set of the upgraded '04 style RSB mounts. They are much beefier than the '02-'03 mounts. Does not include bushings. Used.
02/03 WRX sway mount upgrade
Mounts only - $15 plus shipping
For comparison, if you purchased these new the prices are around $85 for the RSB and $30 for the mounts.
Will post pics shortly.