Here WN57BVT demonstrates how a SmartCar can find a parking space here in High Kingsdown, where one wouldn't otherwise exist.
It may stick out a bit on either side, those inlets may be marked as Keep-Clear, but the truth is they aren't inconveniencing anyone, it's not on the pavement and that keep-clear area has already lost the argument with full-sized cars.
All the SmartCar is doing is making it slightly harder for the cars that shouldn't have been parked up on the pavement beside it to get out, like the rover W498WSG and the mini Vo56ULR which serves them right.
No doubt when Kingsdown becomes a CPZ, there will be yellow lines everywhere and enforcement of the signage, which will remove a vast amount of the parking capacity of the city. Assuming 50% of the vehicles are parking illegally in Kingsdown/Montpelier, there's going to be a lot of unhappy motorists.