If you were to come into my shop without a muffler, being an inspector, I would fail your inspection. Check you local and state laws on your exhaust before taking out our modifying anything. Then ask yourself, "Is it worth it"?
I'm willing to guess that it originally didn't come with the tow package. That the previous owner installed it. So it came with the tow package when you got it. I would recommend taking all of it out and starting from scratch, installing you own.
Touchscreen pioneer radio. 600 watt Rockford amp pushing a 12" shallow mount Rockford sub behind the back seat. That's what I put in mine. My radio started to act up that's the reason I changed mine out.