I also have an 03 3.0.. about 15k ago I had my cv's done, i was expirencing a similar situation, however at speeds over 45 or so it turned into more of a loud "tire/road" noise... but that didnt take place until I let the clicking noise do its thing for like 3k or so..... just to clarify I do not usually let issues set on my X like I did with this issue but i was in germany at the time and I knew that I would be returning to the states soon and I didn't want to pay Euro (man the dollar is WEAK) to fix it, so I did wait to get it fixed, I do not know if that caused further damage or not.. I assume it was not a wise thing to do but ya gotta do what you gotta do..ANYWAY If it were me I would get it checked, I feel the sooner you identify a problem the cheaper it is in the long run... even if it costs alittle up front for them to check and say.." alles klar!!" IMO