[Pinetree]

Image is borrowed from ebay, but you get the idea -- the styrofoam block that holds the inflator fills up about half of the spare tire well. Yours may have actually been the 'spare delete' model.

Well that pic is disappointing!
Here's the link to see a bigger picture. 2014 Chevy SS Sedan Tire Air Inflator Pump Assembly OEM | eBay