Well, some news. I think I found the problem and it's definitely the left drive. I mangled the s*** out of the mounts. The videos I found say "just pull this clip here" or "pop it with a screwdriver" but don't show s***. Well, mine wasn't moving. After tearing up that metal wire clip, I ended up pounding out two roll pins on the door side mount and then was able to knock out the mounting block. Then I tore the s*** out of the body side mount and twisted the f*** out of it until it popped off. Probably screwed myself when I go to replace it. I tried shutting the trunk and it closed and latched. Sort of by gravity and maybe by power. Clearly, the right drive is under some stress in this configuration. I cut the wires for the left drive giving me the option to splice in the new one instead of removing every damn panel from the tailgate interior to reach the plugs.

Took if for a drive and man, is it a smooth runner. Only thing is that there is a rhythmic, rotational sound. At first, I thought it was tire flat spots as it hasn't moved in months but it didn't quite feel like that. Thought maybe brake disc surface deposits but a few gentle bedding stops didn't seem to really change it and I don't feel anything in the pedal. Last thing I thought of was wheel bearings. Could be but in the past I found that braking or accelerating or turning one way or another changes the tone of the sound or eliminates it as the weight is moved around. I'm still hoping it's a brake disc issue since when coming to full stop, the brakes feel "grabby" just as it fully stops and there is some visible spotting on the outside rotor surfaces. It's not a vibration, just a sound.

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8/2011 X5 xDrive35d Sport, Black Sapphire Metallic, Black Nevada Leather, Fine Burr Walnut Trim
2/2001 M5, Jet Black, Exclusive Complete Black Walk Nappa Point Heritage Leather, Black Cubic Trim