Car shaking when in gear and foot on the brake!

[dlh1228]

When I am in gear and at a stop sign, traffic light, ect. and have my foot on the brake my entire car vibrates. Steering wheel, seats, floor, everything. Even my passenger noticed it today. As soon as I put the car in park or neutral the shaking goes away.
I had the exact same symptoms on my M3 and the motor mounts were broken. I had them replaced and this solved the problem. However, I just had all my motor mounts and transmission mounts replaced 2 months ago. I doubt they would wear out this fast.
I just took my car to the BMW dealer today. They said they had 2 separate techs look at the car for 3 hours and could find nothing wrong. The said they hooked it up to the computer and no fault codes or anything. I was told that it "might just be because the car is old!" So I paid $125.00 for a "diagnosis" to find the problem and I I now have $125.00 less in my wallet with no answer as to what is wrong! Anyone please chime in if you know what this problem may be. I really want to get it fixed!