To paraphrase that old Robin Williams skit about the origin of golf I went to TGCOC "10 F***ING times! (google his Golf schtick)
After the 10th visit I got my free oil change. All of the experiences were great except for #7 when the lead guy pops up from under my car with a little container of what he said was dirty transmission oil. His comment was that i was in need of a tranny flush.
My reply was that this was really weird since within the last 15000 KM I had just had my mechanic change my tranny fluid, including a proper flush. Tranny fluid last 80K +
"Oh" he said. He knew he had been caught faking the need for a flush.
When I mentioned this to my mechanic he said that it was not possible to take just a sample, you either drained the tranny or you left it alone.
I went back 2 more times to get my free oil change but my trust in them was gone and I will not be returning.
BTW....prices should now be around $50 for synthetic not in the $80 range.