Thanks for everyone's input! While I really liked the plug n play idea of the Kicker upgrade, I just wasn't sold for the cost... I was able to find another thread on a different forum that I found interesting... The user was able to fit an 8" Kicker Comp shallow mount 300 wt DVC sub in the existing Sony sub enclosure. He powered that with a Kenwood amp run between the existing sony amp and the sub, using the line-level inputs- all for $300...

So I decided to give this a try, with a few minor twists... I'm going with the same sub, however I found a Kicker amp that features the same power output (300 watts RMS @2ohm) with a power sensing turn on/off (in lieu of the remote wire), line level inputs as well as a bass control input. I'm also going to add a set of Infinity Kappa 6x9s to the front doors to clean up the muddiness there and hopefully bring out some of the highs... Complete, I should be out the door between $400-450. Ordering the parts tomorrow... we shall see!

 

Sorry to dredge up an old thread, but did you ever do this? If so how did it work out?

 

Going with the Kicker and and Kicker Comp RT was very disappointing. Minimal gains at best, I swapped amps to the Alpine M500 mono sub amp which also had a power sensing turn on/off and line level input. Huge power difference which blew the sub in minutes, lol. I then trashed the sony box and Kicker sub and went to a JL Audio 10" Power wedge box which fit perfectly under 1/3 of the rear seat. That was the perfect combination! The Infinity speakers sound great and the JL sub w Alpine amp gave me more than enough bass! Exactly what I was looking for