An unlockable Christmas gift has been found in Sonic & All-Stars Racing Transformed by changing the system date to December 25th 2012. The Sonic Stadium has tried this out on the Xbox 360 version and can confirm it works when the Xbox 360 console is not connected to Xbox Live, however, we do not know if this works on the PS3 or Wii U versions.
UPDATE: Gagaman in the comments has confirmed it works on PS3, too.
UPDATE 2: Pete in the comments has confirmed it works for Wii U, too.
To find out what the unlockable is, click the jump, but don’t say we didn’t warn you if you don’t want your Christmas gift from SEGA and Sumo Digital spoiled.