Hmmm, X5 4.4 vs 540i (2000-2003)
Hmmmm, well. I like the 540i alot. But, IMO....the only worthy 540i of purchasing is with the Sport Package. So if it were a non-sport 540i, I'd have to say X5 4.4.
Otherwise, is she looking at getting a new or used X5? I like the new face the X5 got.
And, in the 4.4, you feel the power.
Either way, not a bad choice.