So I'm trying to hook up a subwoofer to my cars stock head unit using an line out converter but I have to pull signal from rear speakers to the loc was wondering if I could use crimp on y splitters to pull signal while keeping the signal to rear speakers. Line out converter is a kicker 46KISLOC2 2 channel. Any help would be greatly appreciated. Just don't want to sink the money on a new head unit and adapters to keep steering wheel controls. for reference it's a 2012 impala with the Bose stock amp. I don't care to spend the 500$ for a radio and adapters as I use the car for a daily driver to and from work only.

Mobile user please excuse any grammar.