"I used to see a car around here and the last part of its registration number was WOG. The driver was black. So I suppose that's OK,"

Howard Jones, perhaps you are unaware of the practice of concsious re-appropriation of derogatory terms? This practice of 'owning' and effectively disembowling the aggression implicit in a usually abusive term, is one that the Black community have been actively engaged in for decades. Hence the 'Wog' numberplate you cite. It's important to be aware of potential irony, when observing a commmunity in the process of re-possessing a familiar term of abuse.