So I bought a left over 2016 GT with 500 miles. Drove her home on the highway and of course she vibrates with a nice accomadating attenuation over 65. Just like my 01 and 03 Cobra. What a bummer. Anyhow...who else has this issue? What fixed it? I'm sure it has something to do with the drive shaft and perhaps a misaligned Irs or is it perhaps tires/wheels balance? I'm just starting to dog into the issue. So any new insight before I head to the dealer is appreciatted.

 

Bring it back and bring a tech for a ride with you so he knows exactly what your feeling.
Then test drive it when you get it back before signing off on any thing!

 

I had that issue. It was so bad it was causing my hands to go numb on long drives. My servicing dealer found that the pinion gear was .004" out of tolerance which cause a wobble in the differential. They replaced the guts to the differential and the drive shaft. Vibration gone.

 

I had same on a different vehicle, after weeks of tyre balancing, numerous replacements of drive shafts, turned out the rear tyres weren't round, changed tyres, end of problem