I think, 20 years from now, with the AGW Scam in widespread disrepute, there will still only by 1% of the cars on the road being electric.
They just can't compete with the practicality, efficiency, economy, performance and reliability of the internal combustion engine. In fact if all factors including energy production, disposal of batteries, environmental cost of component production it'll become obvious that electric cars are far more harmful to the environment than gas.. and it will be looked on as little more than a yuppie fad.
In fact the whole hybrid technology which is notoriously complex and unreliable will go with it. Then we can take the these economy depressing punitive taxes off gas.