2001 X5 4.4i Won't start

[Reagle]

Hi guys, long time lurker...I think this is my 1st post. My 2001 X5 has full battery voltage, the starter has been checked and is fine, the alternator is also fine. When you go to start her, it will just "click". I have had this fixed twice before. The first time, the guy said that it had something to do with the anti theft immobilizer, so he disabled it, and it worked for a while, but then re-verted back to what it was doing before. I take it to someone else, and they took apart the rear battery assembly, and said they found a bad connection and that she is all good to go. Well 3 months later she does the "click" again while I'm fueling up on my way to Whistler with a car full of people. Now I loaded up the back with skis, snowboards,boots and luggage, and figured maybe all that weight and a few speedbumps had loosened the bad connection. I unload everything...jiggle a few wires near the battery and WOW it's a miracle she starts!!! Another 2 weeks later and I'm back to her not starting...doing the same "click" sound. What in the heck could it be??? It's back at the place that found the connection problem, but they can't seem to find the problem again...I do have a small leak coming in the passenger side rear door window(my regulator broke,,,and i zap-strapped the window 97% of the way up.) Could this be contributing to the issue, as it looks as though the wires run up underneath the passenger side floor? And don't forget..although the window is up 97% I live in vancouver where it rains like crazy....Thanks for the help guys!