A->It depends on the surrounding environment of your car. Moreover, the type of contaminant also makes a difference to the service. Urban cities, cities located near the sea, etc. -- each of them have their own set of contaminants. Living in a city like Delhi, one should get his/her car cleaned at least once every month..
A->The service professional will be equipped with all materials required for car cleaning. You just have to ensure electricity and water supply for the service..