Actually there are a couple of cars you can unlock with that method. One of them is the special version of the TVR Sagaris. Google it you will find them.
There is a bunch of SHiFT codes for golden keys on
Borderlands: The Pre Sequel
http://orcz.com/Borderlands_Pre-Sequel:_Shift_Codes
Borderlands 2
http://orcz.com/Borderlands_2:_Golden_Key
XBX is the last column, use the BLACK ones because the RED are no longer valid. Anyway I was able to...
There are two packs available Free for tekken, one is for character pictures you use on the custom player stuff and the others are some stuff you can set in various settings from Nino no Kujin (or something like that, from a japanese character that looks like a marshmellow / drum )