The bazookas have RCA inputs I believe, if it was me I would buy a Lineout converter and do what this guy did on his Murano.
DIY - Increasing / Improving the output of the OEM Bose Murano Subwoofer - Nissan Murano - Nissan Murano Forums
Basically I would get a lineout converter, use the signal that is already going to the factory bose woofer, convert to RCA and into the bazookas. The signal is already fitlered so you'll be getting only lows from this signal, no mids and highs.