Hi,I have had big stereos before but because the S4 is a little on the heavy side allready I just want to keep the standard speakers and amps as they are and change the headunit, is this possible? Do I have to get a specific head unit?
Marty

 

Yes, you can get an aftermarket HU for your car. Search

 

I know I can replace the head unit but which one will allow me to retain all the standard speakers and amp?

 

i think any hu will do as long as you know how the wire's goes where, made sure you gets the right harness

 

What year S4? Bose system?

 

i got the pioneer DEH-P5800MP because it has red buttons so it matchs the rest of the interior i don't think pioneer makes a red button head unit anymore but you might still be able to find one

 

yeah it can be done to keep the factory amp with bose. its a pain. but it can be done, you just have to know how to wire it up correctly. the whole stereo is commonly grounded. but the good part is there is a wire diagram on the symphony II radio. so if you understand what wires do what... it makes it easier