Bought truck brand new Limited Edition. Within a couples of weeks, I noticed random shuddering vibration when driving the vehicle not around 35-45 mph with constant up and down shifting. Took it to Toyota. First they said they could not imitate the issue, then I took them out and demonstrated it. Shuddering is worse and consistent around 35-50 mph. Currently around 2000 miles on odometer. I have taken it to Toyota twice and left it for extended periods. They simply tell me that everything is within specs. They told me it may be torque converter flex lock up. They don't seem to be interested in giving me any more help.