I have an old OEM Model Calarion/Subaru radio/cassette head unit

Model is about 10 years old working fine..
Model: Clarion - Subaru OEM
Model Number: PF-97391

On the rear it looks like it has the standard Clarion C-BUS (13 pin Din)
connection for connecting a cd stacker.

I was wondering if I was to purchase a compatable clarion cd stacker unit.
Would it be compatable with the current head unit? As I don't see any
references on the unit itself or in the handbook in regards to adding a cd
stacker/cd support.