McLaren 570GT (2017) is 153 mm (6.02 inch) longer, 296 mm (11.65 inch) wider and has 208 liters (7.35 ft3) bigger cargo space than Porsche Cayman (2016).
Porsche Cayman (2016) is 92 mm (3.62 inch) higher and 90 kg (198 lbs) lighter than McLaren 570GT (2017).