ahaha

well, ( I havent done research this is just from similar experience) I assume it is parked under the edge of a garage or the side of the building it is next to and as the snow is melting the water is dripping onto the car, (part of the building next to is is wet at the top from what I assume is the water from the roof) because the metal of the car holds the cold for longer as the drips are hitting the car they are freezing. The drips will be in the same spot ( or relatively the same) so one by one the drips build up these spikes, either that or someone gathered a bunch of icicles and created a sculpture

Ice stalagmites, basically