I own a 2013 Chevrolet spark 1.2L, and have recently decided to install a sub woofer. I have installed every component of it apart from the rem wire as I cannot find where to attach this. I have a stock head unit so have had to tap a line out converter into the rear speaker wires. Due to the stock head unit I therefore don't know where I should install the rem. Any photos of peoples installs or any advice would be greatly appreciated.