Hey guys, 
  
Need some help.  I am trying to replace the stock single disc unit with an aftermarket one.  I have the 4 speaker "premium" audio system (no sub).  According to a local shop there is no wiring harness for the edge.  I checked Metra and Scosche, and it is not clear.  I found a harness to keep the aux in (metra 70-5520aux), but no model numbers for a specific harness to integrate an aftermarket headunit. 
  
What harnesses did you use?  Make/model please.  Thanks.