By all accounts, it's been a difficult season for Tony Stewart -- who missed the Chase for the Sprint Cup and has nary a top-five finish in 29 starts.

But the three-time Sprint Cup Series champion's frustrations seemingly reached a whole new level after Thursday night's three rounds of knockout qualifying at Charlotte Motor Speedway.

Stewart will start Saturday night's Bank of America 500 from 36th, last among drivers who made the race based on speed. His best qualifying lap of 186.754 mph was nearly 8 mph behind that of pole winner Matt Kenseth, and almost 5 mph slower than Stewart-Haas Racing's Kevin Harvick.

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Stewart -- who recently announced plans to retire from Sprint Cup Series racing at the end of 2016 -- was none too pleased with the speed in his No. 14 Chevy, and made his feelings known on Twitter.