DS3R Sub Install (sorry if its come up before)

[Cyber_Sonic]

Sorry if this has been asked before

So now Citroen have replaced the engine in my DS3R and im going to be getting her back I want to put my sub in

Will it be possible by taking it to a specialist or will I need to replace the hole MyWay system ?
iv had a look on the forum about it but cant see a definite answer some look like you can as Citroen have there one leather sub thing and some look like you need to fit a new HU

any one have experience with this and know what the back of the stock HU looks like with the satnav system and if it has RCA outs?

I only have a AUX port no USB (which is annoying considering the sales woman told me it did -_-) if that makes any difference

If I do need to replace the HU is there one that will still work with the MyWay computer system with RCA outs ?

Any help would be good

Thanks

[cyclone]

There is a subwoofer in the boot already so just tap into the wires back there.