My EX-wife called her "The Misstress" so that stuck. Now I'm divorced she is "The girlfriend" or "Vettie". Vettie being a take off Betty which was the name of my M16s for 12 years.
Her nickname is "Firecracker", all you Country music fans can figure that one out.
And no naming a car is not wrong. Now having a car for a girlfriend ok ok that might be wrong. But oh well.