Amazon.com: 2007-2012 Mercedes-Benz GL450 GL550 Auxillary Back Up Battery 000000004039 OEM For Passenger Car : Automotive
2013 Mercedes GL550 - How I installed my system(Kicker L7, Kicker amp, LC2i Pro, Kicker amp installation kit, on stock radio). Haven't seen a lot of talk about this, but I know