This usually solves it....another thing is to check the rubber hangers, sometimes they have premature fatigue and tend to sag.pull down on the on the right tip a bit. if that doesn't solve it, get the car up in the air and loosen the connecting flanges, and see if the muffler section had stress on causing it to sit at an angle and then retighten
I have the same issue....but a slightly different scenario. My left exhaust tip seems to stick 1 inch "farther out" past the rear bumper than does the right. I told the dealership about this the day I bought the car, but I was told they would have to take the entire exhaust system off to see what the problem was.
I hope that someone has a quick fix to this. Has Nissan said anything about this problem? Any recalls or anything of that nature?