You will find mixed views on here in reference to z1. Jon seems to be good, at least with me he has been. I can't talk about the work they perform as I have never had them wrench on my car. Try the search function I'm sure what you are searching for will be located. Good luck.
2006 Chevy Cobalt SS super charged (Daily driver/Gas saver) 1994 Nissan 300zx sport 700 Twin Turbo (Weekend car)