StandOnIt
Farm Truck
When it is just one car it probably isn't the tires. If it isn't the car setup then the driver might have something to do with it. It could be from rubbing another car.
it could be the taildragger design is really sensitive and/ or of a design where more load can be applied to the left rear. Johnson had a left rear blow out also in the duels. It might not turn up the rest of the year, sure, there will be plenty of right sides going down, and it could be nothing with the lefts, but every time Nascar makes a change, the crew chiefs don't sit on their hands.