No Coop-Playing. Only singleplayer. Doesn´t require any specific missions. But I haven´t tried to test it with everything.
I just noticed that through a bunch of activities, when I didn´t get the goal on first try.
As I said before, this bug is no big deal for me, since I know how to avoid it.
But I can easily reproduce this. I just started the Steelport - Bridgeport Tank Mayhem activity and let my time run out. (Fail the activity at least once!)
then hit restart activity (don´t leave it! restart from the "you loose!" screen!)
and made the silver medal. (Finish it!)
Went back to the gate and all wardrobe items were gone. (make a sad face
and load a far away, previous savegame)
If you need any gamefiles, just say it, I´ll load it up here.