Wanker

4x4 drivers are vilified on three fronts: the increased likelihood of killing a pedestrian when struck by one of these monsters; the amount of space they occupy in crowded cities (especially in London, where the mayor will shortly introduce a new tax on top of the Congestion Charge aimed at drivers of these cars); and the amount of pollution generated by their gas-guzzling engines.
I suspect that there are a lot of "ordinary" saloon cars on the road, particularly the older ones that struggle through their MOTs, that are much more polluting than newer 4x4s. But it's the pollution argument that has obviously influenced Greenpeace to launch this new viral.