Replacing stereo for 2002 sunfire w/ monsoon system

Hey, I want to add a spiffy new deck for my 2002 sunfire. One problem (or atl east everyone tells me its a problem) I have a monsoon sound system. From what I was told by car audio shops my cars computer and alarm and stuff is built into the deck, so I cant get rid of it without putting it in the trunk. If anyone has any input, or if youve done/tried this or heard of people doing/tring this elt me know, thanks

Yes they are right but not completely. Check this out... http://metraonline.com/locator.aspx?year=2002&make=12&model=382&type=1