rear deck

Hello all, has anyone attempted to add rear deck speakers to their regals with the base 7 speaker stereo. If you have, is their wiring in place or did you need to tap into door wires and wire in the new speakers.

I have a 2014 Lacrosse Premium 2 with the Bose Centerpoint Surround system and am trying to get under the interior side of the rear decklid trim to add more insulation against buzzing/vibration noises that have made themselves more apparent. I’m having trouble removing the C pillars, more...

Well I have a 99 Buick Century, with the Concert sound 2. I thought it was a just a 6x9 in the rear deck so I bought some new ones seeing as the old were blown. When I finally got everything off I saw a 6x9 and what looks like a 2 inch tweeter. Does anyone know how to wire it so the 6x9 does...