We already have Ford as a manufacturer in the system, so you should be able to add a Ford Fusion as a hybrid by choosing "other" from menus where you don't see the choice you want. Here's more info in the FAQ about adding a specific vehicle we don't have yet: What do I do if my car or motorcycle isn't listed?
I don't own a Fusion, however, even though I registered my car as a Citroen C4, which is not listed, it still won't appear in the "Browse Vehicles" tab. Not that I need to go there to check on my own vehicle bout it would be good so I could see other member's cars and MPG. is there no way to do this or am I missing something?