As electric vehicles become more efficient and affordable, there will be a natural transition that consumers make to them. At this point it's mainly about improving the cost and efficiency of the batteries. Expect VW to have a big impact in this regard with their coming I.D. line of vehicles. Reduced demand for gasoline can also have the effect of lowering the price of gasoline. Eventually, California will impose other forms of transit tax so electric vehicles help to pay for roads. I don't see this as a sign of impending regulation upon historic vehicles.
