I am looking to upgrade from the single CD to the Shaker 500 in my 2008 Mustang! Is this even possible with just replacing the head unit?

 

Unless someone gives you their Shaker or you can get it dirt cheap, I'd go with an aftermarket unit. My Shaker 500 has been problem free so far and is ok but not great. Others here have had problems with theirs.

 

asdfg

 

I bought one for $50 and when I called FORD to get it reprogrammed he said that I might have to replace all speakers ETC but he was going to check and get back to me.