Mario Andretti took some hot laps around Charlotte Motor Speedway's road course as part of the NASCAR Racing Experience.Andretti took to Charlotte's 2.4-mile, purpose-built road course in an 887-horsepower 2015 Porsche 918 Spyder Hybrid – which the 77-year-old got up to 177mph – and a 640-horsepower 2017 Cadillac CTS-V.Charlotte Motor...