Leaderboard

Hi Sam and welcome to the Club. I've never owned an IS350 so I can't speak to this with authority. You are right that the front deck speaker is for the navigation voice and to some extent a center channel for music/voice. All three of my ES350 have had the sub under the rear deck or what Lexus calls a package shelf. My 2013 Rx350 has the sub in the right side of the cargo bay. In my opinion, you will never get the low bass response you want without installing a separate amplifier and small sub in the trunk. The amp for the sub allows you to set the output and range of response while giving you excellent sound. I don't know how much room there is in your trunk, but given the small cabin volume I would think you could get good results from an 8" sub. Find a good, reputable car sound shop and get a quote from them. I don't think your dealer would be interested in modifying your system. Come back and let us know how things are going. Paul