I have a dying CD player in my 2005 Trailblazer. I scoured the junkyard today in search of a replacement. I found a good looking unit with all of its knobs in a 2003 Regal. Could I assume that GM used similar stock wiring in everything of that era? I'm unemployed, and a $25 junkyard radio is much more doable that an Ebay $150 replacement. But, I don't want to buy something that won't work for me.