Infiniti apparently figures nothing succeeds like excess. First, its Q50 midsize sedan got a luxurious new trim level for 2021. Now, well into the model year, Q50 gets yet another luxury trim that can be applied to the new luxury trim that it got originally. Huh? To put a finer point on it, the 2021 Q50 is available in trims of Pure, Luxe, Sensory, Signature Edition and Red Sport. Sensory arrived with the 2021 model year while the new Signature Edition, which is based on the new-for-2021 Sensory, began popping up in showrooms early this summer. Regardless, all trims share snappy styling, a 3.0-liter, twin-turbocharged V-6, seven-speed automatic transmission and standard rear-wheel drive with the option of all-wheel drive. In the Red Sport, the twice-blown six-pack makes 400 hp and 350 lb.-ft. of torque. In everything else, it generates a still-lively 300 hp and 295 lb.-ft. of twist.