the only real way to remove zaino is with rubbing alcohol. id recommend just using alcohol on the areas where you see the spots and then z1,z2 those areas. you dont have to start all over again unless your entire car is covered with water spots.

another problem as to why your having water spots is maybe due to what your drying your car with. using a leaf blower is an excellent idea but what do you use afterwards? i personally use the absorber after leafblowing my car.