Monsoon...

[entheos]

It sounds really good IMHO. I have it with the single disc MP3 stereo. If you like your music a little louder once in awhile with a subwoofer while retaining a stock appearance, it is a must, but I'm sure you could accomplish the same or better with aftermarket products though it probably never one that look like stock, nor have all of the big buttons and knobs of the stock head unit, even if the button paint does wear off.

I don't know why GM's MP3 compatibility is so varied for their different makes / models. The G6 has an in-dash changer that reads mp3 discs, and a few of the small "hip" models like the HHR have a line-in jack. Even though I have resisted the ipod so-far, it would be nice to control one with the factory head unit.