For X5 going to east coast there is a VPC across the street from the factory in SC. For BMW's coming to east coast from Germany there is a VPC in NJ. For west coast the VPC is in Oxnard, CA.
I am sure you have seen the big white trucks with white curtains to hide cars and Bavarian Transport or PMTG written on drivers door. They are carrying BMWs inside. Unlike Audis and MBs which are transported in open trucks.

Check this link on what happens at VPC