Hi there. I just purchased a 2018 spark ls in nightfall grey. It has the 4 speakers; 2 tweeters and 2 mids in the front doors. I am looking for advice on installing a woofer and amp. I was originally thinking about putting it in the spare tire hole, but I'm not sure if its going to be possible to get a component cable ran out of the head unit. According to dealer, the infotainment unit doesn't support additional wiring. Hope to hear some insight. Thanks. B.