Are you wondering why everywhere you go today you keep running into priests with STP embroidered on their chasubles sprinkling cars with holy water and making the sign of the cross over yellow cabs driven by Sikhs, Ethiopians and Zoroastrians?* Then I will tell you.
It is of course the feast of St Frances of Rome. Still confused? Frances was a holy widow in 15th century Rome who did her good deeds at night, preceded by a guardian angel - in the shape of an 8-year old child - bearing a lantern. Now you get it. The lantern represents headlights, and headlights are on cars and even though Frances never saw a car, she is a saint and Italian and that is enough to make her the patroness of cars and cabbies.
St Frances is sadly ineffective at repairing dents, dings and scratches; on the other hand, and don't quote me on this, I have heard that she has a special relationship with the Parking Authorities.
* While Catholics used to hold the world record in the Conversion-of-the-Unwilling-and-Those-who-Already-Have-a-Religion Sweepstakes, they have recently been overtaken by the Mormons.