assuming youre not talking about auctiva eBud, Auctiva Poster, or Mr Poster - when you are creating a listing,
http://www.auctiva.com/listings/createlisting.aspx there's a drop down box for selecting US, UK, or eBay Motors.
If the box doesnt have those choices, you should file a support case.
http://www.auctiva.com/help/requesthelp.aspx