 Bought my 2006 Xterra new... LOVED IT.  The design was awesome.  It was a bit rough (its a truck after all) but comfortable overall.  Powerful engine, though hard on gas.  All sweet for first 3 yrs/ 65K miles.  After that things started to all apart.
Fuel sensor crapped out so I couldn't tell how much gas is left based on the fuel gauge.  The driver windows stopped working.  U-joints went.  By the time I passed 100K, the transmission fluid leaked into the radiator and vice versa.  Spent $1500 to replace the radiator and flushed the trans. only to have them tell me that I need a new transmission - $4-$5K (at 110K I wasn't able to go in reverse).  Couldn't afford it so traded it at a loss.