I bought my Vx in Vegas and on the drive home, had the same problems that you have... Still under warranty, two dealers tried to fix the problem. One dealer replaced the front dif and the second replaced the rear dif. After two different reps checking the problem out, they said the noise is normal but is very loud. After the last visit, I noticed something that the dealer did not do... rotate the tires. When I purchased the car, the original owner had to buy a new tire because of a blowout which made the originals slightly smaller because of tire wear. The originals were worn to a point that I bought 3 new tires. After the last dealer visit, I measured the tires and the (now) older tire was about 1/8 to 1/4 smaller. By rotating the older tire on all hubs, I have different sounds. If on the front right, 60-70 on accel has noise on decel, on right rear, 60-70 has noise on float or decel. On right left, I get noises at 40-50, slight grind-whirl with traditional rear end noises, with the older tire on the front right hub, I get harsher noises at 60-70. The least noise was when I put the smaller tire on the right rear and pumped up the pressure to about 45psi. This made the diam. of the tire the same as the 3 new ones at 30psi. Now the noise is very slight when the tires are cold but after about 20 minutes, some of the whine comes back at about 65 (slight on decel)... I think I am going to cough up another 180.00 and buy a new tire next week and will let you know the results. I think if there was a way to disconnect the TOD and just run on 2 wheels on the freeway, the noise would be gone, but I dont know if that is possible.