Awesome man! Would be great to see some in-car vids.
In September I'll be taking the X5 to a semi-private driving event at a security specialist training installation (Blackwater). Here's some track info:
U.S. Training Center We should be running the full course.
Did you ever feel the X5M start to roll? I know what you mean by the rear end rotating feeling, but haven't pushed hard enough to feel one side start to really lift.