Mini Cooper D useful for short distances?

Hello, in a few months I will buy a new car, but I am not yet clear which one. Criticisms are design, economy and driving fun. So I thought of a Mini Cooper D. I drive about 5km of city traffic twice a day and at the weekend also sometimes 30km highway and country road. On working days the vehicle is then moved only very briefly, in the morning maybe 5-7 minutes, in the evening thanks to traffic also sometimes 20. The taxation in Austria is different with diesel than in Germany, my Knowing is identical to a similar strong gasoline engine. Of course I would prefer a Cooper S, but consumption, insurance and new car price rather speak against. Greetings