I agree with you on the touch free, its good to get most of the stuff off however it does leave a “film” of dirt when your car is caked in salt. So you need to physically brush it off via wash mit or brush. Stay away from any brushes at the selfserve car wash, they are too stiff and cause swirl marks and marring on the paint. They also are full of dirt and even little rocks, people use it to wash their jeep that covered in bud, and I’ve even seen someone scrubbing the underside of their car with it, so the that’s the last thing you want to put on your paint. Your best bet is to go to a self serve wash with your own mit/bucket.