How can i hook up subwoofer for Acura Tsx 2009 because i want to upgrade the system to 15" kickers?

Will it void the warranty?|||Hold on... you have a 2009 Acura TSX and your putting your system in yourself? Wow... uhh i know how I put system in my Type S i paid a professional. I see reposetion in your future...|||You can bet on that.|||buy a high low converter and some t-taps to tap into the rear speaker wires then run your power wire and tap your remote wire to something like the positive of the cig lighter. then you can hook your amp up and run a rca cable from the high low to the amp and you have subs