When Keva was about that age I was also asking advice on car fixation. I tried prong collars,spray collars,tin cans with coins,yelling and looking her in the eye and telling her I was going to have her for supper. She is now 14 mo and I'am happy to say she seldom looks at a car.Patience Patience and more Patience and just keep letting her know it is unacceptable!.
Good Luck.