The All Weather Package didn't come into being until May / June 2008 - if your car was manufactured before then, it may not have the defrosting windscreen wiper section.
It's hard to tell for sure from the historical records if the early MY 2009 Limiteds (manufactured early 2008) came with heated seats and foglights exclusive of the All Weather Package, but it looks like they did. This may explain why yours doesn't have the defrosting windscreen wiper section.
