Well, I suppose I have to comment on this, the latest "move" by the British Government in support of their "carbon-reduction" policies.
Let's see how this works. You trade in your existing gas-guzzler and buy an electric vehicle or hybrid gasoline-electric vehicle. The new car comes with a fat subsidy. I wonder where the money comes from?
The new car also has batteries. Heavy batteries that contain toxic materials. So large and heavy that a four seater car becomes a two seater car. No room for the kids, then?
The all-electric car will have a range of around 150 miles, maybe less, and all of £20 million will be invested in providing charging stations around the country. But charging takes many times longer than re-fueling at the pump, so journeys will take longer, assuming there is a charging station handy. In this case the hybrid does seem the more sensible option.
Of course, electricity is still largely produced from burning carbon-based substances - oil, coal and gas. The amount generated from "environmentally friendly sources" is woefully small and unpredictable. So the point of generating carbon emissions will change but the amount of carbon emitted will not. If anything the amount of carbon emitted will increase because of energy losses down transmission lines and the fact that electricity is generated whether or not we choose to use it.
Which is why gasoline remains the world's most efficient and portable energy source.
Finally, one more thought. That old clunker needs to be scrapped, disposed of, even re-cycled, requiring even more energy, just as the new vehicle also requires energy to be built.
If people wish to buy an electric or hybrid vehicle, let them do so. That's their choice. It is the incentive that's ill-conceived.