the mounting kit you ordered is correct, axxessinterface.com will have what you need for steering wheel controls. i am not 100% sure on the power harness adaptor but it looks like a standard nissan adaptor for rockford or standard radio re and re. just be sure to hook up the amp turn on wire (blue wire with a white tracer stripe). if you like fm radio the pioneer is a great choise for its stronger than most tuners. i am a car audio installer but have not done any xterras since they were still new to the market. also some nissans used a double diversity antanna and you will need the adaptor for that too. hope this helps. new here and as far as i can tell i will be owning a 1st gen xterra within two weeks...fingers crossed