Yes, the hub is identical
Same 5x120 PCD and same 67.1 mm centre bore: wheels from MG Marvel R bolt on and centre on Opel Insignia B 2.0 Turbo 4x4, GSi without rings. You still need to check the offset and tyres, detailed below.
≈: width estimated from the original tyre size.
Wheel by wheel: offset and tyres
Each original wheel from MG Marvel R is compared with the one from Opel Insignia B 2.0 Turbo 4x4, GSi of the same diameter: how much closer the wheel gets to the shock absorber or how far it sticks out of the wheel arch, and whether the tyre keeps the same overall diameter.
- ✓
≈7Jx18 ET50 · 215/55R18 — Fits like the original
Compared with the original 8Jx18 ET41 on Opel Insignia B 2.0 Turbo 4x4, GSi: shock absorber side −3.7 mm, wheel arch side −21.7 mm, tyre diameter +3.7 % : fit it with the original tyre size of Opel Insignia B 2.0 Turbo 4x4, GSi (235/45R18), not that of MG Marvel R.
Comparison for guidance only (estimated width). Check in detail
Before fitting the wheels
An identical hub is not enough: offset, width and diameter change the position of the wheel, and larger calipers can touch a smaller wheel. Original wheels often use bolts or nuts with a specific seat: keep the fixings intended for the wheel, with the thread of Opel Insignia B 2.0 Turbo 4x4, GSi (M14x1.5), tightened to the torque shown on its vehicle page. Finally, check that the size is among the approved fitments for your vehicle. This comparison is for guidance only: have the fitting approved by a professional.
And the other way round: wheels from Opel Insignia B 2.0 Turbo 4x4, GSi on MG Marvel R?