Subwoofer buy what?

Hello to all who look at the topic, so I’m about to build a little more power in my car but less in PS than much more in watts what did you use as a subwoofer? what should I look for? my questions go especially in the direction how much watt do I need so that it sounds good and has a proper bass? I don’t want the mega hammer stuff with 5000W or so but what do you need minimum with it sounds good and what do I have to pay attention to in the amplifier in connection with such a subwoofer. the 2 conditions that I should have. not overly high price and he should not fill the whole suitcase(something more related with a suitcase or a box beer next to it) thank you for your answers already. greetings