Just bought a 2002 xterra 4wd S/C for my wife. For $6000 108kmiles on it. The X rides like shit so I replace all of the shocks, but I went to auto zone parts and bought some shocks they where 35$ each. The front seems smooth know. The rear shocks not so smooth it seem that the old shocks where better. The thing is in the rear shocks when I hit a small bump there a knock in the rear like the shocks bottom out. Need help what should I do thanks