Used car shopping – smells huge

Moin, I used to buy a nice BMW here, but the conditions are so stupid that it stinks already. Was on an online market, contacted the seller via email. The price was indicated in the market at 8,000€, 40,000km. Reply mail then came from an email address with female name of a French woman. Broken google translate German. Car is on her name, she “has taken the car from Germany and now the car is in Frank Tüv would be rich until 5/2018, divorced from her husband, car reminds of him, wants to sell him as soon as possible, pushes the price down to 6000, if I go to the Franco-German border Strasbourg and take it with me. S/W tires in the price, “all taxes paid in Germany” (which taxes?), service booklet completely maintained. So damn good offer. Then comes what I don’t get at all. All papers will be ready for a sale, and I can also use the same To appease again, it is suggested that you go to some workshop nearby and let the car look at. Questions: Don’t you have to deregister the car here in Germany first? Otherwise you could just theoretically say that I stole your car. And then her name still hangs everywhere in the papers?! Supposedly, the thing is completely fine, how would I/she have to proceed here? The thing just stinks. But if that were a serious offer, I don’t want to miss it either! Hope for input and thank you in advance.