With my wife, both times there`s pretty much nothing she could have done to prevent the shunt. First time she`d been stopped for about 10 seconds while the car infront of her turned right, the second time she had stopped at traffic lights and again it was 10-15 seconds before the other car hit her. Very poor driving skills on the part of the other driver both times, regardless of any excuse people want to make for driving into stationary objects.
As for the roundabout shunts, there`s plenty of time to glance right and be aware of traffic on the roundabout as long as you leave a sensible gap between you and the car infront. If you`re too close and the other car stops then of course you`ll drive into it.