It is a great idea to keep your car, truck, suv or mini van clean.  Doing so helps keep it in good condition and maintains the investment you have in the vehicle.  But do not use laundry or dish soap when doing so.  These fine cleaners are designed to remove tough grease and grime from your pots and pans and dirty clothes.  They also cut right through the wax you had applied or applied yourself to your vehicle.  Get a soap designed for washing cars.  They will get the job done and leave the wax or coating in place where it belongs.