Cars Playset Vault

maybe it unlocks a concept art gallery or a easter eggs

^i would love this. As a game that is all about collecting, I'd be ok with collectibles that show exclusive art, not just toys, although toys are great too:-)

I'd prefer rare exclusive toys than art that's just me

You can see that the 5th slot is not covering the vault opening so this is not needed to open the vault!

Here at the pirates vault that I pictured at an event, the figures that you still need to collect cover the vault opening slightly to be unlocked:

Nice pictures!