I know the some of the 05 and up xterra's have issues with the length of the A/C drain hose not being long enough. The hose that lets water drip to the outside is located on the passenger side firewall. You can access it, and see it by removing the passenger tire, it has a large rubber cover that covers the port where the water comes out. Nissan has a TSB for this and has a part number for a water hose that you cut and attach to the hose to lenghten the tube. Hope this helps.