McLaren 570GT (2017) is 138 mm (5.43 inch) longer and 310 mm (12.20 inch) wider than Mercedes B-Class (2018).
Mercedes B-Class (2018) is 356 mm (14.02 inch) higher, 100 kg (220 lbs) lighter and has 116 liters (4.10 ft3) bigger cargo space than McLaren 570GT (2017).