As to the question of a diagnostic print-out. That is easy. I can print you one saying about anything. Plus I could make your car exibit and be diagnosed as about anything. It you don't trust your technician; documentation will be the wrong kind of help.
My advice is to find a shop and get to know them. This may only happen at independent shops, but I know hundreds of shops serving thousands of people on a first name basis.
I have been in business for 24 years and plan to eventually limit my problem solving skills only to service customers. If you want to do business with chains (?? to save money??) be prepared to always have an adversarial relationship with your diagnostic technician.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician