Vehicle water wash in service centres

How come authorised service centres don’t use water to clean vehicles anymore but local cleaners with car and bike wash can do it ?

I remember those days when a vehicle goes for servicing on service centres it is totally clean and nowadays they don’t do it, getting car wash now requires extra money, time and efforts.

And on the other hand local car wash can use the water without any issue, and that is why there are so many car wash Centers have opened up in Bangaluru.