McLaren 720S (2019) is 251 mm (9.88 inch) longer and 279 mm (10.98 inch) wider than Mercedes A-Class (2015).
Mercedes A-Class (2015) is 237 mm (9.33 inch) higher, 72 kg (159 lbs) lighter and has 138 liters (4.87 ft3) bigger cargo space than McLaren 720S (2019).