Wasted Cache | Side quests South Park: TSoT Guide

It is worthwhile to cut through all the trash to reach the bag

You receive this quest from Mr. Mackey, at the community center (you will gain access while completing the Find New Allies quest). He will give you his key to his storage at U-Stor-It (you enter U-Stor-It by climbing onto the trashcan, next to the homeless merchant. Inside, enter the main hall and press the button with padlock, at the counter, to gain permanent access). Enter the storage and leave the monitor on the pile,, next to the other ones. It is also worthwhile to cut through the pile of trash to reach the probe. Use it to teleport to the other side, where you will find a key to Mackey's post box, which you can use at the Post Office. Inside, you will find some potions and some money. Once you are done, return to Mackey and he will become your friend.