How to transfer a vehicle? Question about the short-term identification mark

Hello, with the short-term identification marks a lot has changed since Spril, so that I somehow don’t see through there or have a mistake in thinking. But maybe you know another possibility for my problem. I bought a car from private. the seller hands me the car off on 01.09. Since the home of the VK is a bit away, I would hate to drive to him again to get the papers…. above all he wants to register the car only on 01.09… I do not understand why I need the vehicle registration number (certificate of approval part I) when I admit to a short-term registration mark, if it is withdrawn there and destroyed…… Above all, you read different information from county to county, which documents is required. Where is the joke for a short-term registration mark for a deregistered car, if no registration certificate part I exists after deregistration anymore? Or where do I do a short-term registration mark for a deregistered car? n Thinking mistake?! And for a registered car I can not make another registration with short-term registration marks? Or not? Or not? Or what? Unfortunately I don’t know anyone who lends me red numbers from Tuesday evening to Wednesday morning. So basically only the papers of the registered car remains to be fetched on 01.09 and then to let them go on Wednesday and then again and then pick it up. Does someone know with it and can explain to me what I now have Achso: the car has Tüv until 08/2017, so that’s not a problem. A copy of the Tüv report is also available to me, but seems to be of no use in my district.