Well the service manager drove down for a whole day ridealong, which was great that I didn't have to drive the 100+ miles to the dealer. He wanted to see if the problem really did exist still after the last visit. It took me about 15 miles of driving before I could recreate the problem. But once I did, I could make my car jerk for 3 city blocks. He tried unplugging the O2 sensors but that didnt work. He agreed it is a strange problem that has them stumped. He left the loaner car( 09 535ix) and took my x3 back to try one more time with the regional eng. He told me he would bring the car back fixed or come up with some compensation for the issue.
Guess I will wait and see what goes on from here.