In the case of the former, the drivers seem to have picked up on the fact that their cars are super safe and, therefore, they don't have to worry if they hit anything [particularly bikes], whilst with the latter, Rover drivers are usually so old and senile they have no idea what's going on around them!
Well, I now have another marque to add to the list of "cars to avoid/give a wide berth". In the space of about 4 miles on Friday I was carved up by no less than 5 Audi's, all making unsafe lane changes, either joining or on the M25!