Cadillac is testing the limits of its brand allure and pricing power with the 2024 Celestiq – a large, bespoke electric car that will start at more than $300,000. The vehicle – unveiled Monday night – launches the General Motors brand into the ultra-luxury segment against the likes of Bentley and Rolls-Royce. It’s something no American brand has successfully done in modern times. Executives say the vehicle is more about creating a “halo car” that helps burnish Cadillac’s image, rather than fueling overall sales or profits. But, if successful, it could create a new two-unit business model for the company:...