It is not worth the risk! I have had my car washed there several times before and the washes were good but the last 2 times I felt were potential accidents waiting to happen.
The first time the truck in front of me decided to put on his brakes while in the wash, luckily there had been a good deal of space between us and he came to his senses it in time and let off the brake before my car was pulled into his.
The second time the wash was pretty much empty. No cars in front of me when I pulled in, but someone had come in right after me, for some reason the attendant let this second car pull in right behind me with very little space between us. It seemed like an unnecessary risk and I was little dismayed due my last experience there. There is no reason the attendant couldn't just wait a bit and space us apart since there was no one but our 2 cars getting pulled through the wash.
I just can't trust the system here, people are stupid and accidents can happen but
you should at least be able to count on the attendants to care enough to take that into account but they didn't.