My rear doors have been creaking...embarassingly loud for 2 years now. I think a combination of MI winters, heat extremes, and a sh*tty design have all played a part.

Like a lot of us...I sprayed the hinges down with WD-40. Works for a day..then "Creeeeeeeeeeeeeeak."

So...after using PB Blaster to remove/install new springs/struts/control arms on my 535i, I took the can and sprayed down the hinges, but this time I took the little red tube...jammed it into the rubber boot on the door side of the door where the arm goes in to keep the doors open, and let it rip until fluid was leaking out of the little boot. Did both on top and underneath the little arm going into the door.

Result: No more squeaking or creaking!! Its been 3 weeks now. So even if I have to repeat say once a month...that's good for me.