This is my first post to this board so I hope this is not veiwed as "spam" but I'm just trying to help out a room mate. My roommate is selling his 2004 C5 now that he is building a house. Below is an eBay link that shows several pictures of the car and has a video/soound clip of the sound. If you have any questions I can be contacted at kylew5@hotmail.com.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=4597241565&sspagename=STRK%3AMESE%3AIT