i do believe that this test mule drivers are instructed to get away from the people with cameras, me and my brother were chasing a test mule 760li on a freeway on 101 a couple of months ago (i was recording from a cell) and he got got pissed floored it, but since it was traffic he couldn't shake us, but when we were getting off the freeway he gave us the "dirty look" and shaked his head
it was a lot of fun chasing him around though.