I went to one once and it was the only time I ever had someone else change my oil
It was when I was moving and had no place or tools to do it and in bad weather.
Long story -short- they told me I had a bad transmission leak.
I said how bad.He said bad. I asked How much fluid did I lose and he could not tell me.
The fool invited me into the shop to show me a leak but I wanted to see the dip stick.
The fluid didn't lose an once and the dip stick was now standing next to me.
A lot was said after that. MY oil change was completed
and i went to somewhere to have it double checked. Rick