Hello, a buddy of mine would like to buy a used Volkswagen Golf 8 soon. He asked me to come with him because I own VCDS and OBDEleven. I should check the vehicle for him. My question to you would be now, is it legally allowed to connect to a vehicle this diagnostic device? The vehicle belongs theoretically to the seller. Do I have to inform him about it? And what do I do if he does the verification g denied by the diagnostic device?