Big combo with 6 cylinders?

Hi everybody, I’m currently looking for a big station wagon for my mother. She wants to have a running 6 cylinder gasoline truck with automatic. The car is driven most of the time over land and highway and 4 to 5 times a year she wants to go with the caravan, where the routes are never more than 500 km. Overall she would drive with the vehicle about 15000 km a year. The “new” used one should be at most 10 years old, at most 150000 km have run, leather, automatic As a budget it has 11000 Euro and an Opel Signum 2.2 directly with 150000 km. Since it is also supposed to be a German car, the selection is now more garn me, because Opel and BMW excluded it. Now I have found the following vehicles that come into the closer selection. 1. Mercedes E 350 with 7 gear automatic, here I have seen check booklet cared cars from year 2006 for approx. 10000 to 12500 Euro. 2. Passat 3.2 FSI with 6 gear DSG, Sch eckheft gepflegt, built in 2006/2007 for approx. 9000 to 11000 3. Audi A6 3.2 FSI with 6 gear DSG, checkbook maintained, built in 2006 for approx. 10000 to 12000 I would be interested in reports about driving characteristics and maintenance costs. Whereby not the fuel consumption or the taxes/insurance are meant here, rather, I am interested in maintenance and wear parts costs. However, there is also one or other car which would be recommended. Many greetings from Stade