It seems I don't yet have enough posts to enable editing, so I'll just add a reply to anyone who reads this far. After pulling the dash to add a Grom Vlite, I traced wires back and found a satellite radio unit was added. So, it's a satellite radio antenna. There was about 25 feet of wire coiled up under the passenger carpet and the module is mounted under the carpet against the transmission tunnel. Two of the wires on the satellite harness run back underneath the passenger seat. I unbolted the seat and found the wires are spliced into wiring for to the Mark Levinson amplifier. I'm not sure what they do, but I left the harness coiled underneath the carpet, just in case something went awry, I could hook it back up. I've been running the Vlite for a few weeks now with no issues (other than quirks of the Grom unit), so I'm about to cut the satellite radio harness free and pull it out along with the antenna. Next to install the GPS antenna and microphone to finish off the Grom install.