BMW 8 Series (G15) (2018) is 1 mm (0.04 inch) longer than Opel Insignia (2014).
Opel Insignia (2014) is 182 mm (7.17 inch) wider, 157 mm (6.18 inch) higher, 266 kg (586 lbs) lighter and has 120 liters (4.24 ft3) bigger cargo space than BMW 8 Series (G15) (2018).