At the last 2 GM dealers I was at, they no longer give you that backup paperwork showing part numbers, labor hours, fluids/quantities, shop supplies, etc. They have it printed out, but they don't let you have it. You sign a single page cover sheet that you are paying $X and accepting your vehicle as is after they performed X service, and then you get an unsigned, simplified copy of that one sheet back. If you had 6 services performed, it shows a half-assed description of only the first thing they did. When I said hey, we used to get all of those backup details, the Service Mgr smirked and said yeah, and labor used to be $75 an hour, too, and closed the window.