He was still there about 6 months ago when I used them last. This time I dropped the car off with a list of things I wanted done and when they called to say they were finished and gave me to total I was surprised because it was too low. I asked if they did everything on the list and they had me talk to the mechanic to go over what he did. Turns out he didn't do anything on the list but fix the injector, and it didn't seem like he knew z's at all.
And yes, I'm aware of the injector problem. I just had all of my injectors replaced (by Nissan) during my 120k (16k miles ago) and one is already dead and the dealership that did the work is out of business.