Greetings all. New to the site, but seems like we have some very knowledgeable people around here so I'd like to ask for some suggestions and/or information. Firstly, I have an '06 GT with the Monsoon system. I used to be fairly heavy into car audio so please feel free to talk techie if need be. Since getting my GP, I have found that I miss my "loud music" as my son calls it so I am wanting to explore options to upgrade the sound a bit.

First question - is it possible to upgrade the deck and retain the steering wheel controls? I thought that I heard some GPs came with a touchscreen but have not found any evidence of this. I used to be all out with the 24-bit Burr-Browns and high V pre-outs, but no need for all that, I just want to make certain I have a clean, quality signal being sent.

Second question - I see that the stock speaker sizes are 3.5" (dash), 6.75" (front door), and 6x9" (rear deck). Taking into consideration that proper impedance is observed, is it simply plug-and-play with aftermarket speakers? Are all the stock speakers coax, or true components?

Third question - I would like to add some low end to the system through subs (potentially a couple of 10s or a ported 12). Are there any setups that have worked well in the GP (ported, sealed firing up)? Should I be aware of anything if I were to simply upgrade speakers and add this to the setup?

Thanks, in advance, to anyone taking the time to help an old man trying to recapture a little youth.