Friction v.s. Touch-Free carwashing
Writing for friction carwashing
Simply put, there needs to be friction to get a car clean. I personally believe that with the outside factors and conditions changing from day-to-day - from temperatures of cars coming in, the temperature of the surface of the car, the temperature of the outside and weather - I think you really need soft friction to end up with a good quality product time after time.
The truth is that the chemistry, when you're only touch-free, is the only thing you have to rely on.
It's like trying to wash your hands without rubbing them together. You can stand there and put as much soap on your hands as you want, but if they don't come together your hands won't really come clean.
Writing for touch-free carwashing
The old argument regarding friction vs. touch-free washing is that friction has a chance of damaging a customer's car and that touch-free possibly doesn't clean the car as well.
I think that this argument had more teeth a few years ago. I think that it's lost some of its merit over the last few years, specifically the last five years.
Friction systems have gotten far better at being safe for the car and touch-free systems have gotten far better at cleaning the car.
I believe that the playing field is leveling off, and I think this may become a moot point in a few years. That being said, there are some definite benefits to touch-free washing.