So i have all the DLC's (got gold edition) and so far I can't figure out what this DLC is where to find the stash or even what it is or does can I have help? (Also how do you get the Pimp Boy 3000? I'm on 360)

The Couriers Stash is a mash up of all the Pre-Order equipment bonuses (there used to be 4 of them, you got one depending on where you pre-ordered the game from before release)'

Anyway, they are added to your character's inventory when you are talking to Doc Mitchell during character creation. I believe it will add the items to an existing character if you load them up while having the mod (DLC) checked in the launcher or mod manager.

You are not supposed to use all the items, but you can if you want.

I have the tribal courier mercenary and something else cant remember (as well as the xpansions) thanks for the help tho I thought there was a safe with tons of loot somewhere XD