I got my '03 4.6 a year ago this Feb with 58K I now have 88k. The only reason I bought it with that many miles was because it was CPO'd. Im glad I did because it has had almost 15,000.00 worth of warranty work in one year.
It is an awsome vehicle to drive but it can get pricey if you dont have warranty. I traded in an '01 4.4 with 150k that never had the problems that the 4.6 has had. Both have the cold start knock which drives me crazy. I have not had enough time to search on this site for the knock concern. I have always been a sports car nut but after driving an X for five years now I cant see any reason to drive anything else as a daily driver.