Did some looking and don't see anything that details that part.

Looks like door panel replacement (ouch).. or get creative. About the only other option I could give you would be these guys.

LKQ

They seem to deal in quite a few Crossfire parts.

Got to thinking old school.. carb linkages that had a retainer..rod slipped through and it "rolled" down and clipped to the rod. Might take the rod and parts to a local auto supply when they aren't busy and see if someone would take some time with you. Here's another avenue..

http://www.ebay.com/itm/1999-2007-Si...item4ab39ae9f6