Mercedes SLK-Class (2014) is 30 mm (1.18 inch) wider, 202 kg (445 lbs) lighter and has 35 liters (1.24 ft3) bigger cargo space than Opel Ampera (2014).
Opel Ampera (2014) is 364 mm (14.33 inch) longer and 136 mm (5.35 inch) higher than Mercedes SLK-Class (2014).