Sandbags in pickup bed, placement?

I voted for right over the axle. Build a sort of box around and between the wheel wells with 2x4 or whatever and place the sand there. At the back or bumper I'd think it would be more difficult to control the vehicle if it starts swaying and sliding around. Studded tires are a great idea but you really should run 4. Unless you dont mind losing your steering and 70% of braking power on the ice and snow....