Fixture control switching
Edit: Also, the super car body has an issue with tweaking fixtures on its rear end. While selecting parts you've already placed on the rear end, one of two things will happen.
A: It will select through the car and select something on the opposite side.
B: If there is more than one instance of a particular fixture (IE a lip) it will manipulate both pieces or prevent manipulation of either if it detects a second one.