If i change the radio unit with the Aux port still work?

[PX54]

Title pretty much says it all.

I've got a radio from my old car and i was wondering if i put it in my DS3 would the Aux (and steering mounted controls) still work?
I'm guessing it might depend on how i set it up i.e. if i connect everything at the back.

[Dangerousfish]

I'm guessing it might depend on how i set it up i.e. if i connect everything at the back.

Exactly that, and providing the headunit is compatible.