I have a 2014 CX5 grand touring with the bose amp and navigation on the stock head unit . after much research I have come to the conclusion that the factory amp is bad . my plan is to buy an aftermarket head unit will I be able to just replace the radio and still get sound from my speakers ?my plan is to elimanate the factory amp all together if this is the case do i need to run all new speaker wire to the doors ? . my other thought is to add another amp this would be my first attempt so any info would be much appreciated