I recommned:
www.ezsubaruparts.com I just orderd the V2 SPT Battery Tiedown and Oil Cap (steel) for $30.60 and $27.17. By far the cheapest I found on the web through all the OEM part vendors. Shipping was only $12.95.
Also www.subarupartscenter.com I had really good luck with these guys. I bought a fog light lens from them since mine was cracked by a rock. It was only $89.30 and they ship fast.