BMW 4 Series (2015) is 68 mm (2.68 inch) longer and 92 mm (3.62 inch) wider than Mercedes CLA-Class (2016).
Mercedes CLA-Class (2016) is 55 mm (2.17 inch) higher, 100 kg (220 lbs) lighter and has 25 liters (0.88 ft3) bigger cargo space than BMW 4 Series (2015).