Hi.
I'm new to this forum as well as car audio.
I hope some of you more knowlegable people can give me some advice on the problem I've run up against.
I want to upgrade the stock audio system That is currently installed in my '09 Corolla.
So far I have had my four doors and trunk sound matted and I am going to mat my floor, headliner and under my hood. I am doing this to help with road noise as well as with the audio sound quality.
Also, I want to improve on the factory stock system.
My stock head unit has a six disc cd player and so far all the after market units I have come across are sinlge cd units. This brings me to my main question.
If I retain the factory head unit what can I do to improve the quality of output?
If you feel that what I am trying to accomplish is impractical what would you recommend that I do?
I really want to retain the multiple cd capability, but I am trying to avoid having to take up room in the trunk with a remote unit. I'm hoping to reserve that room for a small sub.
Thank in advance for any suggestions you may have. As I said at the beginning I'm a novice at this so if my questions seem a little dumb to you, I ask your patience.

Thanks,
Ed