2020 Mazda CX-5 NON-Bose install. The hardest thing about this install was finding the signal source. There was absolutely no information on the internet at this time as to where to tap into. I obviously used the tuner/amp wire harness but the signal source could be tapped into the center pillar on each side as well. wire colors are the same. you would have to run the wires to the back of the car and connect them to the Line out converter there. Hope this was helpful for some.
Link for LOC
SCOSCHE LOC80 Car Stereo Speaker 2-Channel Audio Adjustable Level Lineout Converter https://www.amazon.com/dp/B00009UHRE/ref=cm_sw_r_cp_api_glc_i_fA31Fb841VZXW