Hi guys, this was posted by another member but no one answered. perhaps i shd be asked differently. my 03 accord has navi but is not "xm radio" ready. the kit honda sells goes under dash and you lose that extra cd compartment. the 04 and above navi units are sat/xm ready and will play using the onboard radio controls that are built in. i think the question was if an 04 or 05 navi unit that is "xm ready" plug and play into an 03 harness...i personally think it would...yet another question is at hand...do you also have to replace the upper display above the center vent? i think that display panel works in conjunction with the main display of the navi also. i'll let the experts weigh in on this!

 

Update: a honda-acura tech told me that the upper panel must also be replaced on 03 models if an 04 or 05 navi is used.