Automatic car washes can be bad for your car because the brushes and chemicals used in them are very harsh on a vehicle's exterior.
It is best to use an automatic wash sparingly or when absolutely necessary, like after driving through mud.
If you do choose to use one, make sure that it has been properly maintained and give your vehicle extra TLC afterward by handwashing with quality products as soon as possible.
Auto washes should only be considered if they have high-pressure sprayers instead of brushes which will help protect against scratches from the ground grit found inside most automated systems.