Mazda 6 – Bose + Woofer?

Good evening! I am recently proud owner of a Mazda 6 sportscombis, built in 2006 with the Active Plus equipment. Now I have the Bose sound system, which is highly praised by the dealer, which works perfectly. Let’s now come to my need: I lack “Wumms”. That means I think about a retrofit of a subwoofer in the trunk. My budget for this is unfortunately only about 250 euros, because I also bought OZ rims for the summer. What would be in this P I listen to music in principle almost everything… Depending on the mood. Hope you can give me a hint, which components I need and how I can realize the end. Mfg