I recently purchased a 2007 Hyundai Sonata Limited and am looking for additional information about the audio system in it. It has a 6-disc Infinity CD/MP3 system, with a six-speaker setup plus a subwoofer.

From what I have read on the 'net and as well as through a search on Crutchfield, it has 6" speakers in each door (four total) and an 8" subwoofer behind the rear seat up inside the trunk.

What I can't seem to find is any mention of the small tweeters in the door frame of each front door. I'd describe them as being exactly opposite the outside mirrors on the inside of the doors. I'm guessing they're 3.5" or thereabouts, but can't find specifics.

I am also curious the specs of the receiver... since it's shaped to the dash I can't just replace it without looking funky. Anyone know the receiver's output? Does it have any pre-outs for my own amp/speaker setup?

The system is pretty nice, but if I want to upgrade I need to know my options.