Rather than starting with an SUV and then replacing the roofline with something faster, the Polestar 4 is a purpose-built four-door coupe that just happens to be a bit taller. It's available with one or two engines producing up to 400 kW (544 hp), and with a 0-100 km/h time of 3.8 seconds, it's the fastest Polestar on the market to date.