It’s no secret that Kyle Busch has thus far had an uneven season in the NASCAR Cup Series. That continued in Sunday’s Coca-Cola 600 at Charlotte Motor Speedway, with Busch finishing P15 in the rain-shortened race. After the race, Busch described his run at Charlotte as a “seesaw night.” “It was a seesaw night for the zone Chevrolet team in this year’s Coca-Cola 600 at Charlotte Motor Speedway,” Busch said, via John Newby of NBC Sports. “We were off the mark early in the race battling a loose-handling Chevy and struggling to get through traffic. We ended up one lap down after our first pit stop…