new secret side mission?

[brad]

as i was playing i ran across a locked side quest marked box with no side quest on the roof a a buck a slice anyone know anything near creek loop

[Crimsomrider]

Locked quest containers (stashes) are tied to the nearest NCPD event, so in order to access it you need to first clear out the event nearby and loot a conversation shard off the bad guys which will give you the quest to loot the stash.