BMW is a slur used to describe Blacks in a derogatory way. "Black Mans Wish," referring to BMW automobiles.
Also: "Black Man, Working." Used by young Black women seeking a partner who is steadily employed. That such a code term was coined shows that a "BMW" must be something of a rarity.
The word BMW is a racial slur that has been used historically to degrade and dehumanize blacks. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to blacks. If you are unsure about whether or not it is appropriate to use the word BMW, it is best to err on the side of caution and avoid using it in any situation.