Good day!!
I think you will get as many answers to this as the number of members that respond... I honestly don't think I had one leave me stranded... I had an alternator lock up on me that in short order (on the highway) converted my alt belt into a hot blob of melted rubber... I nursed it home by shutting the motor off and coasting when I could...
My sisters battery died due to the alternator failure in Silvester (2006 4.4L)... I went out to save her... Actually, my alternator lock-up happened the same day I went out to save my sister... What are the odds of that?!!
I buy them cheap and fix them up, so I'm constantly keeping up with the Preventative Maintenance (PM)...
The pre-face lift (up to 2003) has the M62 motor and a 5 speed auto... The electronics are not as picky... I personally like the N62 motor better... It has more issues with electronics... Both have issues... But, they both have their advantages...
I am partial to the 4.4L... I have a variant in "Red", my 4.6is... Here is a shot of my "family"... The loner in the front is my son's E46...
I rebuilt the motor in the 2004 white one you can mostly see... And the motor in my sisters 2006... The white rebuild is on here, but I'm updating the pictures...
I also converted the 2001 white one that is mostly hidden into a RWD 4.4L 6-speed manual... My better half has taken over driving it daily with Red needing air bags... Becky (black one) is my new favorite...
Welcome to the X5 community!!!
Happy holidays to you and yours!!!