TRENTON, N.J. - Ashtrays have been disappearing in cars like fins on Cadillacs, and so could smoking while driving in New Jersey, under a measure introduced in the Legislature. Although the measure faces long odds, it still has smokers incensed and arguing it’s a Big Brother intrusion that threatens to take away one of the few places they can enjoy their habit. “The day a politician wants to tell me I can’t smoke in my car, that’s the day he takes over my lease payments,” said John Cito, a financial planner from Hackensack with a taste for $20 cigars.