This is not just BMW who do this.
Mercedes have the AMG line trim with badges plastered on their models.
I have the M50d and have no doubts its what I paid for -
tuned by M Sport but obviously not an X5M.
I have paid a premium for this and yes the car is covered in M50d logos but I'm not ashamed of it.
I agree that someone who puts an M badge on a non M tuned vehicle may have a complex about not owning a true M sport vehicle
