Took the Pacifica in to get a bunch of little warranty things fixed along with a loud rotational tire noise when going 40+ mph. Dealer came back and said the noise was because the rear tires were coupling and that they should be replaced and also that the front tires were pretty low as well (I did notice myself that the front passenger tire was much more worn than the rest). Is it normal for these OEM tires to be so worn at 30k miles? Especially so unevenly worn across all 4 tires? Also this 'coupling' i have never heard of and had to look up after i got off the phone with the dealer. He said it would be from tire defect or the way the van was driven and that it most likely was not from something the van was doing.