Driving up the Pacific Coast Highway from Malibu to the Maserati Silver Cup polo tournament in Santa Barbara, Calif., I was flush with the same excitement I felt as a child riding my first big-boy bike. A tap of the accelerator in the passing lane brought a responsive resonance and surge of power from the Maserati Ghibli S Q4, and in that moment I realized that after decades of driving, my training wheels were finally off. Powered by a 404 hp, 3-liter, twin-turbo V-6 engine, the four-door sedan is a family-fri…