I am tired of searching my factory amp had bit it i am getting buzzing all speakers and it dropping speakers then they come back etc etc

Anyways I assume an 08 amp would sound better then my factory 04 are they interchangeable?

 

Buy a good 6 channel amp that can handle 2 ohms. prolly be cheaper and sound way better.

 

Agreed. You can do a good aftermarket amp for the price of a stock amp. Stock speakers sound pretty decent with more power. It will be louder and sound better. If you're planning on keeping everything else stock you need 5 channels or you can do a 6 channel and bridge 2 channels for the sub, preferably aftermarket.

Also, '04 and possibly '05 were different from the rest in the way they do rear fill. I don't know if its in the head unit or in the amp and I have no idea if they're interchangeable.