The rear end tunnel is a tube with a pumpkin shaped indentation in
the center which provides clearance for the drive shaft and the
housing of the differential. It allows the rear end to travel up and
down with suspension motion; it clears the differential housing by a
maximum of three or four inches when the suspension is fully
compressed. The rear end tunnel often forms the front of the trunk
floor. It is attached to the wheel wells on each side as well as the
floor pan and the trunk floor.
