One side of this that doesn't seem to get looked at much is how many ICE cars are on the roads that could be converted. Doing conversions at high volume would be very labor intensive, but it would give dealerships and mechanics something to do, and it would generate less waste than replacing whole cars.
Right now it's kind of on the edge of being practical, mostly because of the batteries. They're expensive and bulky and they need to be fitted to cars that weren't designed for them. 200+ mile ranges aren't really realistic either, because you'd be adding too much mass that the car wasn't designed for. Conversion kits now seem to be a custom thing made in low volume for a handful of vehicles and usually cost somewhere in the neighborhood of $20,000 or so.
On the other hand, if a major manufacturer can buy batteries and motors and controllers at wholesale cost and engineer a conversion kit for their own cars, amortizing the engineering cost across thousands or hundreds of thousands of cars, then maybe you can get the cost down to something reasonable and have something where all the parts just bolt in perfectly and all the car systems work the way they're supposed to. Maybe it can be a simple as walking into a dealership and saying "I want my car to be converted to electric" and they say, "sure, just drop it off for a week and here's what it costs, etc..."
The other day I decided to change the oil in my Honda Element myself and crawled under the car. The gas tank is basically a big metal box stuck to the bottom, with a bar in front to keep it from getting scraped off by a rock. It looks a little ridiculous, like Honda designed a car and at the last moment realized "oh, we forgot about the gas tank; let's just stick it to the bottom." If gas cars are made this way, then maybe finding a spot for the batteries in a car that wasn't originally designed for them maybe isn't any worse.