BMW 8 Series (G15) (2018) is 40 mm (1.57 inch) wider than Buick Regal TourX (2018).
Buick Regal TourX (2018) is 143 mm (5.63 inch) longer, 142 mm (5.59 inch) higher, 242 kg (534 lbs) lighter and has 180 liters (6.36 ft3) bigger cargo space than BMW 8 Series (G15) (2018).