Unexplained vibration!!!

[dlh1228]

After having my 2001 X5 (3.0) in the local shop for the last 2 weeks and having all motor mounts replaced and then having the transmission mount replaced........I still have the exact same problem!!! Hopefully someone can chime in with any possible ideas/solutions.

Here is my problem:
The car seems to run perfect except when I am stopped and in gear. There are no check engine lights on, etc. The problem is only when the car is in gear and I am sitting stopped at a light with my foot on the brake I have a pretty strong vibration. My steering wheel, drivers seat, passenger seat, floor, etc. are all vibrating like I am in a massage chair! As soon as I put the car in park or in neutral it goes away. Also, as soon as I start driving it goes away. I does not vibrate at all when driving. It vibrates the same when stopped if I have the air conditioning on or off.
The shop first said it was motor mounts. I had all motor mounts replaced $$. Went to pick up the car to drive off and noticed I still had the same problem. I was then told it has to be the transmission mount. I had the transmission mount replaced. Went to pick up my car and still have the same problem! I really don't know what to do from here. Any ideas?