Picture this: a new commercial for Toyota’s new car, the Auris. You see a closeup of a woman in red underwear and high heels walking towards a car from behind. It cuts to her face, and then back.

Jan from Toyota — A.K.A. Laurel Coppock — and the more zanily humorous Flo from Progressive — Stephanie Courtney — are America’s most visible TV commercial characters; and they’ve made ...