Been using this for over 5 years with no problems at all:
http://www.acehardware.com/product/index.jsp?productId=1288897 Bonus, it can be used on any other 01-04 Xterra that might otherwise not have a rear tow point on it.
Brent
_________________________
Tip: see if your question has already been answered before asking it. Try our handy-dandy search tool!