Flip Case with Extended battery

I don't know if there's an extended battery for the GSM SGN but I would love to have a case like the one I have for my Iphone which look like that:It should be able to accommodate an extended battery.Al the SGN cases so far flip the wrong way for me to use in my car mount or have a tab that protrudes without being elegant.Has anyone seen or has any ideas about cases of the kind I mean for the SGN?Thanks,Ehud