What is this 2x2 white brick in the shape of a figure driving a go kart? I have a 2x4 white Lego brick in the shape of a figure driving a go kart. It has a stalk to accommodate a head with Lego embossed on it. There is no serial number except for a 4 stamped underneath. Does anyone know what this brick is and what set it's from?
Based on your description, i think you have 

x351 - Brick, Modified 2 x 2 Racer Driver No Head



This comes from:

4593-1: Zero Hurricane and Red Blizzard