UPDATE- Solved the vibration problem
Just wanted to update everyone, mainly because I spent months researching this issue and got no less than a half dozen different answers. This week I had my front driver's side axel replaced, along with the hub and bearing. Not cheap. Over $2,400. I didn't want to chance this so I brought it to my dealer, who I have to say has very knowledgeable BMW trained techs. The problem with suspension issues is not only the physicality in removing parts, but the issue of potentially breaking a rusted bolt or other component, which means a tow and hundreds of dollars more to fix.
ANYWAY, when I got in the car after the repair it was incredible. You would have believed I just drove it off the lot, and mine is at 250K miles. Virtually all of the vibration is gone and the car runs like an animal. I had a look at the old axel, probably original. The upper boot was intact, but water had gotten into it and the joints were grinding, which caused the reverse torque into the engine and created the vibration and "shudder" down the drive train which I would have swore was coming from the center universal. The lower "outer" boot was actually broken open but that joint was no where near as bad as the one with the intact boot....go figure. My bearing was just starting to make a noise so I decided to change it. However my tech said with that many miles, (250K) the race was no doubt worn and it made sense to replace both the hub and both bearings. Expensive, but the car rides almost like new.
Last, like Woody Allen said in one of his sick films regarding the female anatomy, these things travel in "2's". Which means, I will no doubt have to replace the other axel probably in the next 10-15K miles. I may give that one a try because the labor and parts mark up was over $1,700 of the $2,400. May be worth the risk.
The message here is with these cars, don't avoid the real issues. I am amazed at how many threads have trial and error solutions that end up costing the owners a lot of dough and not fixing the issue. The most valuable thing a BMW owner can find for their ride is a good EXPERIENCED tech to either work on the problem issues or at the very least give good advice based on "on the job" experience
Now on to replacing my drivers side window regulator!