For some U.S. drivers, this year's hottest car accessory is a chunk of black plastic. Ford and Rivian gave one to each of their EV owners free. General Motors is selling one for more than $200. And ...

Ford and Rivian gave one to each of their EV owners free. General Motors is selling one for more than $200. And drivers of other brands will have to wait until they, too, can obtain an adapter — and ...