A friend of mine just sent this photo showing how he picked up a Dr. Mercy-type rifle from a random loot drop in the Southern Shelf. I noticed that the bottom right corner shows "Backpack 98/33"… how is he carrying so many items ?
EDIT: I should mention that he's on a PS3. He and I play single-player, as he doesn't have an internet connection at home. We communicate by email on his phone, so his messages are terse and sometimes cryptic. When I asked him how he did this, he said something about maxing out his inventory and then trading somehow with a second character that he brought up with another controller. I still don't get it. I've only ever had an additional inventory slot when I received a mission reward and already had a full backpack. Guess maybe I should actually call and talk to him… 🙂
Best Answer
Mystery solved... my friend said that he's simply never sold any inventory items, so the extra slots are all from mission rewards!
He has the GOTY edition and has never gotten any game updates because there's no internet connection at his home, so this may not work for those of us who get regular game updates.
He also said that a drawback is that you can't pick up loot or buy from vending machines, so you have to use a second character as a mule to carry and pick up things for you and then trade with them.