Dog car cheap in maintenance

Hello together I am looking for a new/used car and hope that someone can help me. I have saved some money and am looking for my first one car. I still have 2 big dogs. Therefore I am looking for a car with a large trunk or the possibility to fold the back bench just to do such a dog box in the car. In addition, the trunk should not end too sloping. In price I have 2500-300€ available. The less The better it would be of course. What would be very important to me is a cheap maintenance of the car. That means cheap in tax and insurance and if possible relatively low fuel consumption. So far I have considered the Honda Jazz which would be available in my price range only with 150,000km + and that seems to me a lot. Maybe someone still has an idea here ? I would be happy about any help Dear greetings Kaja