Used car: Reliable combo up to 25,000 EUR. Manufacturer certificates?

Hello together, I have to buy a new used one. Budget is up to a maximum of 25k€. May of course also be cheaper. Age should not exceed 3 years and 60.000km. I don’t need much equipment in itself. Parking aid, seat heating, air conditioning, cruise control, electric seats and mirrors suffice. (Or is there still a must-have nowadays?) The only thing I care about here is good connectivity to the smartphone. Performance, from 150 hp, due to the current It is also important that it is family friendly (combi) and offers travel comfort for long distance on the motorway. Otherwise, reliability is crucial. It is important to me that the technology is as robust as possible. The choice of brands is about: Audi, BMW, Mercedes, Seat, Skoda, VW Since I don’t have a look at the used car market at all, therefore the question which cars are currently best suited to the requirements, and which ones offer most for money. t you recommend the Hersteler certificates? So e.g. “Young Stars” from Mercedes? It is important to me to keep the risk as low as possible after the purchase. Which certificate would be the “most efficient”?