So I bought used audi a3 1996 and it has a subwoofer that looks like it was installed by audi. The speaker is 6.5 inches and 2x3 ohms. So I don't really know what could do as a replacement speaker. Also there are 4 pins on the speaker so I don't really know how that works. These are the pictures of the old sub: https://drive.google.com/file/d/1m8sb_eDuybnPbQCISu6D5d2R31tM38bl/view?usp=shari ng https://drive.google.com/file/d/1waYEDlC6FgGSYKBNJwlbIyzW6xQvJ1-a/view?usp=shari ng