I have been reading different posts and was suprised to hear other people having the same problem as me. I have a 06 double cab tacoma 4x4. Ever since I got it a weird humming noise would appear around 30 mph and go away at 40 mph. It wouldnt do this all the time, it might happen one day and wouldnt show up again for a couple days later. I finally took it into the dealer with around 2500 miles on it. I took it for a drive with the mechanic and he heard it, so we drove around trying to figure out what it could be. He asked if it did it in four wheel drive, I said I have never tried it. So we waited for the humming noise to show up, and once it did I popped it in to 4WD, and the noise instantly went away. We tried it a couple times and every time it went away. So now I have to take it in later this week and they are going to troubleshoot more and hopefully fix the problem. Well I just wanted to hear from you guys if you had the same problem and what the outcome of your experiance was?