I found it a little wierd that after many months living at the prison, that the Biker Bar, the surrounding neighborhoods, and everywhere Rick and Michonne and Carl were this week hadn't been absolutely picked over by that point. These were all withing walking / limping distance of the prison, and while the houses had been visibly ransacked there was plenty of stuff left over. The Walmart or whatever from earlier this season was also pretty healthily stocked...
Beat me to it.
Also remember Rick and crew said they were doing a spiral pattern (around the prison) for several months (between seasons 2 and 3) before they actually found the prison, they were reduced to cans of dog food.
Rick and Carl could not have gotten more than a few miles from the prison the way Rick was moving, so that area they settled in should have been picked clean a dozen times over.
Also here is an international traile
r that has a few more tidbit scenes from upcoming episodes AND
A spoiler pic if you click this link