Is the passenger side rear tire on the drive wheel on the '03 Cobras? The reason I ask, is that it has significantly less tread on it than the one on the driver's side. 6100 miles, and I like to get on it frequently.:??:
Right side does spin more than left until Limited Slip kicks in, as torque reaction of drivetrain is to drive left rear tire down and lift on right. That's why you mount your battery in the right if you move it to the trunk. Never really saw that cause really uneven wear though. Is the wear throughout the tire or just one area? Maybe alignment is off.
It's some sort of defect. My stock rear tires were worn down to the cords in 8,000 miles. My wife doesn't believe me. She wants to shove a 2X4 up under the gas pedal. At least I think she said "gas" .