So I was at a bmw dealership with a friend of mine over the weekend who is looking at an e46 M3. When I mentioned to the dealer I had an '01 X5 he told me how he doesn't buy any X5's before '03 because they have "too many problems" I thought surely he means '04? But sure enough he had quite a few '03's on the lot.

The only differences I've heard about between '01 and '03 (aside from the addition of the 4.6) is the third brake light added in '03.

It's just been bugging me since he said that.. were there really any significant mechanical updates between these years?