Have the dealership download software update for transmission and check all mounts upper and lower. I need to change my lower subframe mount. Don't know if I can do by myself or not. The dealership seems somewhat reluctant unless you have a message from car computer. Let me know what you find out. Mine is still shuddering at 40 mph

 

Turned out to be bad idler pulley. Thing eventually broke off, but managed to get home with no alt, ac, or power steering