Well it does say that the 2012 5-door Focus has removable head restraints so that suggests a fold-flat rear seat (60/40 type).
But I don't think you are going to get a fully assembled bicycle into one without at least taking the front wheel off. I think you should take that requirement off your list and just use a hatch rack. REI makes any number of inexpensive ones that are very easy to install. I can carry two bikes on the back of my MINI and it's not a hassle.