I am new to having a hummer so I have a quick question that has probally been answered here before but I can not find it. I just recently purchased an '07 h3 and was wanting to change out the head unit. Can you just get a wiring harness and go with it or do you have to change out the speakers (like the case of my last car)? or anything else? what all is needed and is it a hard job to do?
I am looking to put in an Alpine headunit with sirius,Ipod install and all.

 

please contact to your dealer tell him the problem