According to Car and Driver's latest review of the Taycan, rear-seat space is capable of seating someone who's 6'5".
It's a Four-Seater Sedan for a Reason, and Not Simply an Electrified Panamera
Meier says the sedan configuration was chosen because the Taycan needs to sell in high enough volumes to meet worldwide regulatory requirements that a sports-car could never achieve. But Porsche was determined not to lead with a SUV because it wanted its first EV to be as dynamic as possible.
However, it's not simply an electrified Panamera. The Taycan is a size-class smaller, with aggressively sloped hood- and rooflines. In fact, sitting in the passenger seat, the hood appeared to plunge faster than that of the new mid-engine Corvette we sat in recently. And the Taycan has a trunk versus the Panamera's hatchback because the space required to package the hinges on a hatch would've either negatively impacted rear visibility or raised the roofline.
Rear-seat legroom in the Taycan is quite generous, although the top of this six-foot-five evaluator's head was just brushing the optional glass roof in the car we rode in; Meier says that the rear-seat headroom is about an inch less than the Panamera's. Part of its rear-seat spaciousness was enabled by strategically removing two of the battery pack's 33 individual modules from the area where rear passengers' feet reside, dropping the floor there more than three inches. As passengers slide their feet further under the front seats, though, they'll notice a steep ramp back up to the floor height found in the rest of the cabin.