If you are going to use git/Dropbox like that (and I can't say I really recommend it in the first place) then you should keep a bare repo in dropbox and use it

If you are going to use git/Dropbox like that (and I can't say I really recommend it in the first place) then you should keep a bare repo in dropbox and use it as a local 'remote' (check out working repos from it on each computer that you are working on, and push/pull to/from the bare repo in Dropbox).