Thou shall not drive under the influence of alcohol. Thou shall respect speed limits. Thou shall not consider a car an object of personal glorification or use it as a place of sin.
The Vatican took a break from strictly theological matters on Tuesday to issue its own rules of the road, a compendium of do's and don'ts on the moral aspects of driving and motoring.
A 36-page document called "Guidelines for the Pastoral Care of the Road" contains 10 Commandments covering everything from road rage, respecting pedestrians, keeping a car in good shape and avoiding rude gestures while behind the wheel.
"Cars tend to bring out the 'primitive' side of human beings, thereby producing rather unpleasant results," the document said.
It appealed to what it called the "noble tendencies" of the human spirit, urging responsibility and self-control to prevent the "psychological regression" often associated with driving.
The document's Fifth Commandment reads: "Cars shall not be for you an expression of power and domination, and an occasion of sin".
Asked at a news conference when a car became an occasion of sin, Cardinal Renato Martino said "when a car is used as a place for sin".
One part of the document, under the section "Vanity and personal glorification", will not go down well with owners of Ferraris in motor-mad Italy.
"Cars particularly lend themselves to being used by their owners to show off, and as a means for outshining other people and arousing a feeling of envy," it said.
"It urged readers not to behave in an "unsatisfactory and even barely human manner" when driving and to avoid what it called "unbalanced behavior ... impoliteness, rude gestures, cursing, blasphemy ..."
Praying while driving was encouraged.
Vatican City, the world's smallest sovereign state, doesn't have many of the problems listed in the document. It has about 1,000 cars, the speed limit is 30 kph and one Vatican official said the last accident inside Vatican City's walls was about 1-1/2 years ago, resulting in only minor damage.