Hi guys, my son just graduated from the the U of I and got a pretty decent job. So, he bought himself a lightly used Audi 2018 A3 with standard sound, no sub. I am reading that a factory sub can be placed in the spare tire and wires can be run to the MMI. Wondering if anyone had a part number for the sub and possibly a lead on the wire connectors? I am aware that there would be coding to do. Any help would be appreciated. I assume it is similar to my mk7.5R. Mc