My question is what happens to gas stations as the changeover is underway? They make razor thin margins and rely on selling a lot of gas to turn a profit, which leads me to believe there will start to be fewer gas stations even when only 20% of cars on the road are electric (just my conjecture, but it seems to make sense to me).
Now as gas stations start to thin out, that would put a damper on people buying gas cars as they would have to go out of their way to fuel up. Which downward pressure on resale value of cars, making people not to want to buy a brand new gas car if it looks like they won't get any trade in value in a few years.
The only hope that I can think of is when it gets to this point, there would be another "cash for clunkers" type of program to make the transition easier.