Mysterious rash of flat left rear tires reported during Sunday’s race The left rear tires of several race cars flattened during Sunday’s AdventHealth 400 NASCAR Cup Series race at Kansas Speedway. Among those suffering flat left rear tires during the race was Chase Elliott, Cup Series points leader. Tires also went flat during a previous race at Darlington Speedway. The Kansas Speedway racetrack was dry at 2 p.m. Sunday, although there was heavy rain earlier in the day. (Fan photo) Daniel Suarez, car No. 99, was another victim of a flat left rear tire during the NASCAR Cup Series race Sunday at Kansas Speedway. He was in the top five when the tire went flat. (Fan photo) Christopher Bell, car No. 20, also suffered a flat left rear tire at Kansas Speedway on Sunday. Martin Truex also had a flat tire that day. (Fan photo)