I used to use car washes until i took a previous car through an Esso wash near Barnsley one day - it was a black car, and the car wash was faulty (i found out later) - there wasn't any water being put through the brushes...
... so after the "damp" plastic brushes had spent 4 or 5mins going backward and forward over the car, with me inside starting to get suspicious about the excess scratching noises, and lack of suds i drove out to find the car looked like it had been washed with a cat ! there were scraches everywhere.
The attendant wasn't at all concerned, but i took further details, and rang the owner of the site, he then instructed attendant to close the wash (i had already told 3 queuing cars to not use it). After a quote from the garage for about £1000 of work to get the paintwork back to condition the petrol station owner wasn't impressed and asked if he could have chance to repair the paint with a mobile valeter - we sorted out with a letter, so i could still have the option of claiming on his insurance if the valet didn't work, but i'm pleased to say that after about 5 hours work with a polishing mop, and lots of waxes / creams the valet brought the paintwork back to better than it was before i went to the car wash.
So i do cringe everytime i see a car in a garage car wash - it doesn't take much to block a water supply hose, and then you'll have the same problem i had - but as stated above the brushes may be softer than the plastics i got scrathched with about 8 years ago.