2019 Elantra GT N Line, 2013 Hyundai Elantra GT (SOLD)
I believe there is some confusion we need to clarify first. You state you have a "2016 Elantra GT Limited" but there is no such thing in the US. Also, the Infinity system with amp and subwoofer is only offered on the PD 2018-2020 Elantra GT. First we need to clarify which generation you have and then we can go from there. The GD generation did not offer a sound system with subwoofer.