rear tires cupping - loud tire noise o the road

Started having a tire noise and slight shaking in the steering wheel. took it in to the Nissan dlr. who has always done the work on it and they checked the alignment balanced and rotated all four tires. The problem was worse and brought it back and had them rotate the tires back. This stopped the shaking but the noise was still there. I just had an alignment done again and a front wheel bearing replaced and the svc manager came out and told me that because of the cupping on the rear tires the road noise would still be there. early in the game they told me that it was the tires so I went to Goodyear and they said not our tires and that the new cars had too much negative camber(rear). Ok I know from my racing days that that does help handling but I don't race anymore.

I have five more months left on the lease and don't think that I will opt to buy this one.

And thinking back several years I had a ford focus company car that had a real problem with the rear suspension, so bad that in the right conditions the back end would start to come around on you if you weren't quick enough to catch it and the dealer told me there was nothing wrong with it.