If it was not for the subsidies i dont think anyone would buy one.... avoid the London congestion charge seems to be the most common reason to get one....
Then again the government and "RED KEN" have done more u-turns than the playground roundabout so when they drop the subsidy you will be left with a white elephant that is hard and expensive to decommission.
oh except the Hollywood celebrities when its good for the image to drive a PRIUS, and leave the Ferrari at home !