Used car around 15,000€

Dear Community, I (mid-20) am currently looking for a used car, because my Audi A4 has unfortunately blessed the time. I am looking for a compact car with a sporty design with which I want to drive the next years approx. 15-20tkm/year (50% motorway, 50% city traffic). I think this data speaks mainly for a petrol engine. I would like to have the following features in the car: I was so far very fixed on an Audi A3 Sportback (from 2009) the Prob I also saw that an A5 or C-Class Coupe (W204) can be found almost in the same price range and I wonder if I can not get any more for my money. I also like the BMW 3 Series Coupe (E92) very much, whereby the highly praised 6-cylinders are probably over 20,000€, which is a little too high. As you can see, I am still quite undecided when choosing the vehicle model. In terms of design, however, I am very focused on the German manufacturers. Above all, it is difficult for me to assess which models are more likely to cause problems in the long term or where I can easily hit at >100,000km. In short, I am looking for a car with the following characteristics: The specific question would be which models/motor variations you think fit specifically to the requirements profile, especially in terms of reliability. 00 Thanks for your help.