3 - 5 years out and you think battery prices will drop significantly (like 30 - 50%)? The other thing a lot of folks don't understand is the time frame to design, a car. But its a pretty safe bet to say every OEM out there, has math designs already on vehicle in your 3 - 5 yr time span.I don't think it will take 10 years for this change, I would wager in the next 3-5 years this will be implemented.
Chevrolet's brand is all but ruined in Europe, most people associate it with the absolute bottom-tier Korean garbage cars that GM sold here or with the big American V8 icons like the Camaro and Corvette--not a good starting point for practical transportation. Cadillac also holds no water from a marketing perspective. If there was a GM brand that could have led an electric transformation, it was Opel.
Just an example over 2 yrs ago, Organization's for the Blind started a push to require OEM's to have EV's make a sound when moving, there was lots of discussions, and in the US the bill just passed. It goes into effect for all EV's in 2020 depending on how the OEM's respond that might get pushed out further as thats a tight design window. And this is to add a speaker and some electronics that are about the size of a shoe box. To totally drop Diesel engines and replace with Electrics would take a lot longer.
The cool thing about the internet and making future predictions. In 3 - 5 yrs someone dig this up and see where we are. I will be amazed if there is a huge (over 30% market penetration of new cars) in Europe.