I purchased this vehicle certified. Shortly after I purchased it, I noticed a clunking sound every time I put the vehicle in reverse. I took the car to the dealership figuring maybe a u-joint or something simple. Well, I guess Xterra’s don’t have u-joints. They have a one-piece drive shaft. The dealership said that it could be that or something in the rear end. They order parts for the rear end and a new driveshaft. After tearing apart the rear end they ended up putting it back together with the same parts. They said the gears all measured within their tolerances so they couldn’t do anything. They replaced the drive shaft and said things were better. After pick the car up, there was no difference. When I asked them why they didn’t replace the rear end they said everything measured within the tolerances and their mechanic said replacing gears back to factory specs is very difficult. They told me my warranty was good for 100K so keep driving it until it gets worse. Amazing that they acknowledge the problem but can’t or won’t fix it. I’ll never buy another Nissan!!!