SLS AMG E-CELL gets carbon-fibre spine: The SLS AMG E-CELL body shell being shown by Mercedes-Benz AMG at the IAA 2011 is one trailblazing outcome of its ambitious "AMG Lightweight Performance" design strategy. Its key element is a transmission tunnel made out of lightweight carbon-fibre composite material (CFRP), which is structurally integrated into the aluminium body shell and firmly bonded with it.