I have to say. I was not totally happy with Carlos' service either. I found that it was as expensive as a dealer, and in the end, car did not run better.
He "cleaned" the injectors in my 500SL. For the price he charged, he should have just installed new ones. Further, injectors failed a couple weeks later. Did the "cleaning" cause this? I have no way of knowing.
I have gone back to Loeber.
1991 500 SL
2002 BMW 745i
2003 Harley Electra Glide