Cheap/robust car for 200km/day

I am allowed to travel about 200km daily from 01.05. and think about whether I should buy a cheap car (about 2h a day) or whether I drive the route by train (about 5.5h a day, but free)… The car should cost a maximum of 4000€, consume little (max. 6l) and if possible less than 125,000km. Most important to me, however, is that it is robust and I don’t have to go to the workshop all the time, as I can’t afford the fun otherwise. As a filter, I have always searched only for vehicles from dealers with a guarantee and a well-kept checkbook, as this sounds like “safe” cars and I don’t know about cars at all. Is that sensible? Unfortunately, there is no “workshop of trust” in which I could have a car checked. So far I have read that A-classes should be good and robust, but also Mazda 2 has been praised online more often. However, I am open to all brands and models. Thank you very much. in advance for your help.